A couple of hands from a 5$ HU SNG's no limit hold'em. Need an advice

[Kamppi69]

Early on a 5$ sng. Stacks: i have about 950 and villain has about 2050 of course. He seems like a decent player for 5 dollar sng's. Can read the board, plays relatively tight and agressive. I raise to 80 and villain calls(15/30 blinds). Board comes 679 with two hearts. Villain checks and i check cause c-bet with these kind of flops is a no-brainer (comments?). maybe its not. Turn is A and villain bets a pot sized bet under (160). I raise all-in. I dont know what i was doing but what is the best play. Just min-raise or call and see what he does on the river. Villain showed 8T for a flopped straight.

Other hand. Same stake, blinds 10/20. Villain min-raises from the button to 40 and i re-raise 3xtimes to 120 with TT. Villain minraises back and i call. Board comes low cards so i have an overpair. I check and villain bets half of the pot? Stacks are about even. Push or fold?