You wont extract anything unless you actually bet and make it a decent size.

Hand 1: Your flop check is poor. You only have 1 player behind you and even an aggressive player isnt usually going to bluff into 3 other players (who may have only checked because they are checking to the raiser anyway). Expect this to check through far too often. There are plenty of pairs/ draws they could have on a flop like that. Bet $0.80 or so yourself and let them call.
The turn check is even worse given that MP3 made such a tiny bet last time. Do you want another $0.40 or do you want to start building a real pot? The river is a bit meh. Getting it allin is probably correct since he probably does it with any Kx or better.

Hand 2: Again youre betting less than half pot into 2 players on a drawy board. Forget for a second how dangerous that is when you intend to pay off after a draw completes. These guys will check/call down with draws. That means they will check down if you give them free cards and they will only call half pot if you only bet half pot. Charge them properly. On the river I make it $2 and I dont expect him to c/r with worse ever really. Id expect 2 pairs and sets to raise the turn so I think you can fold to the c/r.

Your biggest mistake on both of these hands is that you arent betting enough/ at all when you are ahead.