overall, your postflop sizing seems too small.
hand 1 - fold flop is pretty easy here.
hand 2 - pre-flop fine, flopsizing i prefer 25 or 30, turn isn't really a good spot to barrel. Check-call or check-fold depending on odds.
hand 3 - sizing pre is fine, bigger is a little better tho. Flop is an interesting spot, it's bet-fold barring reads. Turn is bet-fold $1.40 as played. Unfortunately, your sizing makes this a sick spot and i probably call.