Preflop:
I open QJo in the SB and the BB calls.

Flop:
I flop nothing, but the King does hit my perceived range plus I can have all pocket pairs AA-44. I do have a medium backdoor flushdraw with my Jack of hearts. I cbet $0.20 into $0.30. If he calls he's got a lot of pocket pairs and Aces still that I can probably make fold on a later street. Plus Q high might be the best hand.

Turn:
The turn is a Ten and brings a 2nd flushdraw. My cbet didn't mean too much, but if I bet here he needs something to continue, and he will fold a lot of aces and pocket pairs he is holding still. But I was thinking I can still make all of those fold on the river if the turn goes check-check, and I make a reasonable bet on the river. That would represent some slowplayed turns and thinner valuebets. And I do get a free card in case he hit the ten and checks. If I check, it says hey I am giving up, and I think he will bet a big part of his preflop range which in this blind vs blind situation is very wide. So if he doesn't check back, his range contains a lot of bluffs and weak hands that I can make fold with a raise, which is what happened. He made a smallish bet of almost 1/2 pot, which to me says he is trying to take it away or valuebetting very thin and will fold to a raise a lot of the time. I am worried though he will call a raise with a flushdraw, but then again I am even ahead against some flushdraws. I do think I could have gone smaller with the betsizing: I bet $1.35 into $1.04. Anyway, he folds.

It was a dilemma whether to bet the turn, but I was afraid he was afraid he will raise me off my hand with a flushdraw. But if he calls my check-raise with a flushdraw, what am I going to do on a spade or heart river?

you are playing your had in vacuum, while that is good when you have some reads, you are just doing it with to many assumptions IMO and you can get easily exploited, even if villain is not doing it on purpose.

If his strategy is that he is sticky, or that he doesn't stab turn to wide, he will print money since your x/r will be way to wide if you x/r this hand. Try to think more in terms of ranges and what hands are good to x/r for value here and what bluffs you want to do it with and what to bluff on different river runnouts...

Yes I think you are right about the exploitativeness thing, but this is a random zoom guy I had no hands on so he won't actively exploit me.

I do think I can make the assumption about his preflop range being wide because it's blind vs blind, but I had no idea about him being sticky or not. That was indeed a general assumption about how people generally tend to play in these situations. A lot of times you just don't know in these zoom games. There is a lot of guessing versus normal games where you have more reads.

I am going to think about what ranges I would check-raise here and whether it makes sense to have any bluffing hands at all. I should propbably just have bet the turn in this spot.

Like others mentioned you have low visability on your bluff here. Problem with x/r line here is that we probably only folding out no sdw/low eguity bluffs in villains range. IMO x/c line is fine with all equity we got.

I mean, by check raising I am basically representing KK, TT, A4, KT maybe AK, which is a very small part of my preflop range and not very believable. KK is not going to check-raise often too.

I think the play was pretty terrible versus a just profitable bet.

Hands that I maybe would c/r here: TT

You like a check-call line? But what if I hit a straight with a flushcard? or he has A4 and makes a boat when I hit. I wouldn't know what to do. Without implied odds I would need 24.6% equity to call here. I am not sure I'll win 1 out of 4 times if I call. You don't like betting?

small flop, ob turn is the standard line

why do you like overbet turn? what range would you bet for value with that line?

I think it was fine, you have a good draw so this is the kind of hand you want to build a big pot with. I think in general people tend to stab too frequently and rightly so because the population fail to check raise often enough (see comments), you'll likely get a lot of credit with this line and you can raise as wide as KJ bvsb.
That would be my default as well.