Low stakes player here, still learning.

Hand 1... If I'm making a play, then it would be re-raising the flop
Trips don't usually bet out on a non scary board esp. when he's expecting a c-bet
from you.
By turn you have to risk too much of your stack to make a move, sure it looks like a strong ace betting out now that the board is getting scary, but he probably isn't folding an ace or better & you're bluffing off your stack in the dark without any real read on his hand, pretty risky.

Hand 2

I don't think a loose passive raises a flop like this, he calls if he's on a draw,
his big re-raise indicates he has a big hand that doesn't want to be drawn out,
he has at least two pair most likely set given pre-flop play. He wants nothing more than to get it all in on flop here imo.
If u were going to make a big semi bluff I would rather call flop then make big bet if any diamond, 7, 10 or jack hit. I don't do this though.

Hand 3 should work enough for it to be +ev & you got alot of outs.
But even AK might call you putting you rightly on a draw.
(obv. preflop call is bad.)