Re: 3.50 KO 3 handed decision on turn.
Raising pre is fine. Anyone can raise, it's what you do after that counts.
Flop bet seems very good.
Turn is confusing. You lose control when you check. Consider betting 600 to have a better idea of where you are.
As for what the opponent has, it really looks like you are beat unless it's a weird combo draw like Ad2x.