I love the character of Carol as much as the next person — she’s brilliantly written and beautifully acted. However, I can’t discount the fact that Beth is also a brilliantly written character who is stunningly portrayed by Kinney — Seasn 4 conveys her as mature, level-headed, strong and, most importantly, human (which means she’s allowed to have weak moments, selfish moments, and make mistakes — Rick f*cks up repeatedly and no one is calling him an immature, stupid brat). It’s really not fair to judge the actress or the character she’s portraying based off the limited explorations that the writers took with her in seasons 2 and 3.

By Season 4, they finally began to show us who Beth really is and give this character the attention and development that she’s so tragically been denied. And through this growth of character, we see that she’s a completely different person than she was in seasons 2 & 3. She was sheltered and considered suicide because she was scared and it seemed easier than fighting for each day — but she chose life, she chose to become strong and to play whatever role was needed of her for the betterment of the group — so if Rick needed her to be Judith’s nanny, that’s what she was — if Hershel needed her to sing a song to make a prison feel like a home, she did it. These aren’t character points that make her appear immature, bratty or weak. These are points of emotional strength and hope.

Now, I’ll agree that Daryl and Carol share a wounded past and a very strong friendship, but I truly think that’s all it is. I’ve rewatched Talking Dead and interviews and panels and never have either M.M. or N.R. confirmed that Carol and Daryl have ever been in any sort of romantic or sexual relationship. N.R. goes so far out of his way as to state that Daryl is uncomfortable with anything sexual or physically intimate. He’s never put his arm around Carol’s waist except to carry her back from the tombs when she was semi-conscious. He has never once hugged her on screen. He scoffs, grunts or shrugs off her pet names and flirtations in the same manner that a good friend would, and her teasing reminds me of how my dearest friends of the opposite sex and I interact. It’s just playful — nothing romantic about it.

Now, your opinion is yours, and that’s fine, just base it off the facts is all. I respect your opinion and if you’re all for a Carol and Daryl relationship, you’re welcome to it. Just respect my opinion too. I definitely don’t see Daryl and Beth as brother/sister — I have an older brother and he doesn’t look at me like that, and if he did, it’d be super creepy and inappropriate. Just saying. Daryl and Beth are bonding on a level that neither have bonded with any other character on the show. They opened each others’ proverbial closets and cleaned out all of the skeletons, then burned the past down and decided that it was them against the world from that point on. You can’t deny something is there. Just saying that simply because Carol was friends with Daryl longer, that doesn’t make the relationship between Daryl and Beth any less valid or the potential romantic future of the pairing any less viable.

I love how, even though Beth isn’t there physically, she’s with Daryl in some other sense throughout “Us.” When Len starts talking about her, Daryl gets angry, but in the spirit of Beth, he was going to walk away without confrontation. Only when Len suggested it wasn’t an adult like Beth, but a child, like Lizzie, who Daryl was missing, did he pull his knife and threaten to use it (plus, I think Len saying that last bit about little ones foreshadows what may happen to Carl in the finale when the marauders catch up to Rick…). Beth’s influence almost has Daryl cover Len’s corpse, but Len did say things about Beth, and that made Daryl reconsider Len being worthy of Beth’s form of respect. Then at the very end, some reason that Daryl claimed the berry bush in homage to Beth in “Inmates,” when she gathered up grapes for when she and Daryl find the others, stating they would be hungry. The sign for Terminus probably restored some hope that he could find Beth there.

In regards to Carol’s banishment, Daryl seems more angry at the accusation than the actual banishment — I think he’s in denial that Carol, his best friend, is capable of murdering two people in cold blood and then burning the bodies without so much as telling him that she did it or was contemplating/planning to do it. He would have wanted to get her answer himself before she was booted out the door, but he clearly accepts Rick’s words as truth when Rick is actually ready to tell Tyreese. He continues to have Rick’s back, despite Carol. He gets over it quickly enough and, when everyone is split up, it’s Rick who is the first one Daryl mentions regretting not being able to ever see again, while he mentions Maggie as being the first Beth will never see again. This suggests that Carol isn’t as important to Daryl as Rick, personally.

Beth, however, is not friend zoned. Daryl had a fondness for her back in episode 1. You could see that, when she hugged him and he reciprocated in a Daryl-like manner. He’s never reciprocated any gesture of affection from Carol. Ever. He cowered at Carol’s physical contact and rebuffed or scoffed at flirty gestures and words, which feel like playful teasing between friends. But he touches Beth a lot between “Still” and “Alone,” and Kendra’s right — he gives her the serious smouldering stares. It definitely looked like Beth was still trying to decipher the depth of it when Daryl went to get the door a second time, but walkers interrupted a conversation that I truly hope that we’ll get to see play out next season when they reunite.

I have a horrible habit of meticulously dissecting character motivations, especially since the writers of TWD are very careful to paint these people as beautifully human and realistic in their reactions and behavior. So, that being said, this could get long, but I think you‘re the kind of person who would clearly appreciate this:
1) As you pointed out, we’ve never seen this particular side of Daryl before. We’ve seen him friendly, concerned and sympathetic. We know he’s a good guy who cares about the people he’s appointed himself the protector of and that he empathizes with Carol as a fellow wounded soul and sees Rick as the brother he wished he’d always had. But with Beth, he rises above and beyond anything we’ve ever seen from him.

2) Daryl has spent 3 1/2 seasons shying away from physical contact when it’s too intimate. With Beth, though, he doesn’t just accept physical contact without hesitation, he openly initiates it or returns it. He touches her A LOT in “Alone.” It’s more physical contact that we’ve ever seen him make with another character in 4 seasons. If he’s not touching her, he’s looking at her with that very intense stare that suggests there’s a lot of stuff going on in his head — and since this is a new feeling for him, he’s probably confused and, the emotional stuff isn’t his forte, so how to convey it verbally or if he even should is clearly kicking around in his head. Luckily, he says a lot with his eyes, and Beth read that last look loud and clear.

3) He plays house! We see, right before Daryl carried Beth into the kitchen, that the table is perfectly set — and since Beth clearly didn’t do it, that means Daryl did. He was anticipating actually sitting down and having a meal with Beth. He starts off in one scene across from her, but by dinner time, he is sitting right beside her as she’s writing her thank-you note, suggesting that maybe they’d be okay staying put for a while.

4) He symbolically drops his guard with her. People keep asking why Daryl went to the door the second time armed with merely a pig’s foot. Well, I think it could be taken as a physical representation of an emotional state. His guard is down with Beth, completely down. He’s having faith that something good can actually happen to them. He’s just as caught off guard by the walkers at the door as he is when Beth is abducted.

5) He wants her to sing. Personally, I don’t think Daryl ever took any real issue with Beth’s singing. I think he called her out on it in “Still” because he was projecting his own feelings of guilt, anger and fear onto her. But, he clearly appreciates something about it, as he secretly watches her play for a while before realizing his own behavior and he lets her know he’s there, only to ask her to keep singing and playing.

6) He doesn’t call her optimism silly. When she asks if he thinks it’s beautiful that someone would remember the Walkers were people once, he just stares at her as though in her he can see all the good in the world, and he doesn’t belittle her silver lining outlook — he doesn’t say anything actually, which suggests he’s trying to see through her eyes instead of shooting her down.

7) He hasn’t given up on hope. He chases Beth’s abductor’s car through the night and clear into the next day until he comes to a crossroad, where he loses the trail. He collapses from grief and exhaustion and seems unable or unwilling to move from that spot. Some part of him wanted to lose hope, but the fact that he protected himself against Joe and his gang, suggests that Daryl isn’t giving up yet, which means he’s still holding onto hope in some form. Otherwise, he’d have just let them kill him. Before Beth’s influence, Reedus himself said Daryl probably would have ‘checked out’ if he’d ended up all alone after the prison collapse and never had Beth there to show him more.

8) As you pointed out, when Rick told him about Carol, Daryl was in abject denial, stating, “That’s not her.” Not only has Daryl closed a door (or rather burned down) his past, he no longer has this morose and broken shadow of a past hanging on his shoulders. He’s also not likely to recognize Carol in the same light as he once did when he discovers she truly did murder Karen, David, and later on, Lizzie and Mika.

9) Carol and Tyreese clearly have something, a chemistry, or at least they did before Carol confessed — and even then, Tyreese forgave her, though he’ll never forget what she did. Their relationship would be complicated, but well worth it; Daryl and Beth’s relationship is also complicated, but richly rewarding to watch and for the characters themselves. So, I have high hopes for Caro and Tyreese.
And, since the writers are famous for stating something in the beginning of an episode that foreshadows later happenings, let’s just recap that Daryl did say to Beth in their first scene that, “All the signs are there, you just have to know how to read ‘em.” This is just my interpretation of everything, just an opinion. If you’re reading this and you don’t agree with my views, that’s perfectly fine, just don’t burn me for it.