Basically I have moved recently to 400s and Im slowly starting to adjust. I actually like this limit much better because its much more sane and its easier to put people on hand ranges.
Anyhow I had 2 situations that I really played awfully today.

Hand 1:
Preflop
I have 400$ in the hand and villain has me covered. I have no reads on him. He raises in CO to 16$, SB calls and I decide to squeeze/valuebet my to 64$ in BB. He cold calls and SB calls as well. At this point, since i have no reads on CO I put him on AQs+ or TT+ while his range could be a lot tighter(AK, QQ+). SB could have any 2 hands at this point, but most likely a PP.

Flop
Pot: 192$
SB checks, i bet 145$ CO pushes for 354$ and SB folds. Hero? At this point I need to call
209$ into 691 pot. So i dont have pot odds for hitting flush+set outs. Would you bet less here and risk being pushed off a hand, but still folding to a push?

Hand 2:
Preflop
I have 400$ in the hand and villain has me covered. He is running at 28/24/11 over 60 hands sample. So sample is quite small. Anyhow, its 5 handed, CO limps and he raises to 16$ in OTB. I hold in SB and decide to raise it to 52$. He cold calls. Again this is bad sign and the range is at least AQs+ or TT+ at this point with no reads.

Flop
Pot: 112$
I lead out 76$ and he instapushes for about 600$. I have 268$ behind me. Hero throws his wireless mouse into a wall and then does what? Ive kinda under bet the pot here, with only a 67% pot size. A 85$ could possibly be better but i don't think that it makes much difference here?

In both hands I'm not sure if villains are capable of making moves in raised pots, even if they are making a move I don't think I'm a great favorite(vs 2 overcards or such). My table image should be fine, maybe a bit aggressive but not anything that would cause this players to tilt, especially since they don't know me yet.

hand 1 is an insta call. he could easily have something like As K here, red queens. In general if you have an overpair in a 3bet pot, you want to get it all in.

hand 2 is an insta call for the above reasoning.

when you're playing 400nl in shorthanded aggressive games, overpairs in 3bet pots = nuts.