PP $20 + 2 SnG Bubble Question

[DVaut1]

Blinds 150/300

BB Hero 900
SB Villain 2000
Button 550
UTG 4550

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UTG folds
Button folds
Villain completes

Villain isn't particularly loose or aggressive. He seems pretty tight and looks like he's playing ABC poker.

Hero's action?????


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Second question:

SB completes, Hero checks. Except now we know Hero's has Ac7d.

Flop: 7h 4c 3c

SB checks. Hero's actions? I assume it's auto-push on the flop, but given the short stack at the table, I wouldn't mind a confirmation that I don't have a leak if I'm auto-pushing here.

Obviously, though, I'm more concerned with what my pre-flop action ought to be. I assume, with the SB open completing, he's either trapping with a monster or he's got rags, because he knows I'm folding almost everything here, even if he only min raises. Given that he's tight and predictable, I think that might give pushing even more of an edge. So when he open completes, it seems +EV to push any two, given the blinds on the table is 2/3 of my stack and he's folding enough to make it +EV.

However, I've made this play a numerous times at the 22s (pushing any two in a situation similar to this, against what I thought were relatively tight players) only to get called by Q9, 54s, etc. So unless he has A6-A2, I'm really hating getting called here. And while unlikely, it's not outside the realm of possibility that he calls with something mediocre.

Any thoughts?