I was playing 2/5 this past weekend live at a Dog Track in FL on vacation

Im sitting at the table when the table first starts, we play 6 handed for a while, then the table fills up, the two people involved in the hand come to the table after we have been playing 6 handed

Villain 1: Obviously a regular, alot of players/dealers greeted him and said hello, was also MORE than bankrolled for the game seeing as in the first 1.5 hr at the table he had dumped ~$1200 most of it to one other regular when he kept showing up with second best, he straddled every hand, raised his straddle, and then moved in on the flop with ATC

Villain 2: A woman, another regular that looks kind of like an old man, shades, pretty quiet, is sitting on Villain 1s left, and hasn't had very many show downs, but has been making big bets on most rivers

Hero: sitting in the 1 seat, has turned $350 into ~$700 and has been playing ABC showing down big flushes and straights

[INFO] Player in seat 2 is a regular also, and tipped Hero that V2 likes to make BIG bets with 2 pair on relatively safe boards, and gets paid off alot on her overbets [INFO]

Hand Action:

Villain 1 (BTN): straddles for $10 [approx $60ish behind] (had been losing the entire game, and looked to be on tilt)
Villain 2 (SB): calls $10 [Villain 2 is playing $180ish]
Hero (MP1): calls $10 with A5
2 More MP limpers call $10
Villain 1(BTN): bumps ~$45 more and is all in
Villain 2 (SB): calls $45
Hero: calls $45 (thinking more people will call behind, and If not get a checked-down showdown)

Flop 8K10

Check, Check (V2 checked fast as if she was content with checking the hand down)

Turn A

Check, Check (Hero checks at this point because his hand has pretty good showdown value on a clean river card, and can call a thin river bet)

River 9

V2 moves all in for ~$150

Hero tanks.......totally confused, trying to put the V1 on QJ or some kind of really big hand, thinking out loud, and asks the table to give me a minute....

About 2 minutes into my tank.....the All-In V1 starts talking randomly, and then asked V2 to show him her hand so he can go ahead and fold....but V2 shows no emotion, doesn't answer the question, AND TO MY KNOWLEDGE SHE did NOT show her cards, and just sits quietly without any reaction to Hero or V1

Couple seconds later V1 mucks his hand face down, before my action, with him being ALL IN

At this point Hero is VERY confused, and it looks even FISHIER, Hero thinks about calling the floor, but realizes it is pointless, Hero decides to fold his very weak Ace and move on and leave from the table while I am still up 400+

Couple Questions
1. Should I have bet the turn?
2. Is this a pretty standard fold on the river, or was this a shove from V2 because I masked the strength of my hand by checking (honestly looked like QJ suited to me)
3. Should I have been worried about collusion/softplaying etc.? And how do you deal with this in a poker room?

1) I would have checked turn like you did
2) IMO standard fold, old ladies don't bluff here
3) IMO no collusion, V1 is just a bad player

Pretty much this.

River is a super easy fold. Never a bluff. You need 2 pair or better to even think about calling river.

Bottom line, you are never ever winning on the river, fold and move on. Not exactly a good board for A5, which incidentally either loses to or ties all the other Aces.

River is a super easy fold. I don't think I'd get roped in to playing A5cc pre for 1/4 of effective stacks LOL.

I'd probably bet the turn since this villain is probably not making thin value bets with lower pairs and doesn't have a K or T from her described expression. I'd assume in this hand she had QJ or 67, or some kind of flopped monster if she was hoping to induce. Unless you can say otherwise I doubt she's putting in 1/4 of her stack without some PP or something at the least, so sets are in her range too for sure imo.