Hand 1
blinds 600/1,200 ante 200 (9 handed)
Utg+1 raises to 2,800. (UnKnown ~100k)
CO flats (unknown ~80k)
Hero in BB with A3 off and ~65k
Complete from the bb or fold?

Hand 2
Blinds 600/1,200 ante 200 (9 handed)

Villain limps from HJ ~175k (known Donk, caught bluffing a lot,plays alot of cash games with me)
SB completes ~50k
Hero in BB 67o ~65k checks

Flop A 64 (5,400pot) sb checks
Hero bets 2k, V calls, sb folds (9,400)pot
Turn 5
Hero bets 5,100, V raises to 20,500 , hero contemplates raising all in but calls
River 10 H checks, V checks

Ways to play any spot differently or sized different??

H1: Just fold, not too much good can happen there unless you flop two pair or trip threes (or a wheel lol). Against unknown UTG raise you are always in an awkward spot with that hand OOP

H2: If you are convinced of your read, the hand is well played. You could check the flop, but betting is fine. As you said he is an LAG maniac, so his raise OTT doesn't mean too much. That being said, if he decides to get creative and sticks in a huge bet OTR, what are we gonna do? (being OOP here sucks balls). This is why pot controlling (c/c,c/c, check) would also make sense (also to give him enough rope to hang himself).

H1. Whatever.

H2. Flop is whatever. Check the turn, after betting and him raising just fold.

Your insight is whatever

Hand 1:
I would ve completed from BB and proceed cautiously on the flop.

Hand 2 :
I would have c/c c/c and c/decide
As played would ve folded to the raise on the turn.

fold
c/c line

hand 1- ez defend with a/wheel card
hand 2- bet a lil smaller otf, turn check, riv - try to get there next time

betting flop small for protection is fine > better than checking imo

I like c/calling turn too. My read was that he was weak and i fully intended making a hero call on most rivers. I also felt he was the type that would call an all in with a flush draw, no matter the odds, which may be a reason to gii

hand 1 - fold

hand 2 - c/call turn is right .

flop - 2k bet is small here ,I would bet from 3k -3.8k by doing this will eliminate 3 betting from villain.

turn - 5k bet makes villain clearly eliminate holding A on you . would choose 4k-4.5k for 2k flop bet and 5.5k - 6.5k for 3k flop bet .

your bet sizing is not that good