Hand 1: Preflop, being OOP postflop, I raise at least 1bb more. For some reason at 25NL that makes a difference.
Because villain is unknown and this is 25NL, consider your flop bet for value. c/f is to consider as well imo.
B/c turn is good.

Hand 2: Either take your flop line and c/f turn, or 3bet flop.
I think I'll choose option 1 more often at 25NL, because players are generally very passive.

Hand 3: Calling flop is better.

Hand 4: I fold because someone with a 0.34 AF doesn't do this often enough with A9 or worse.
Of course you would expect him to bet the turn with 2pair+, but players at this level don't know what they are doing, but they don't raise much with draws, especially on the turn.