Final table Aruba hand

[Ghazban]

Final table of the 100+9 Aruba tourney on UB. 97 entered so 1st place goes to Aruba and everyone else gets diddly squat. CO (T29,780) has min-raised at least 3 out of the 5 previous hands and is playing very aggressively. 6 players left and blinds are 400/800 with antes of 100. I have two red kings, a fairly tight image, and T8345 on the button.

UTG and UTG+1 both fold, CO min-raises to 1600, I re-raise to 2400, the blinds fold and CO calls. Should I have pushed here? He's been raising so often that I don't have a good idea of what he's holding. With such a good starting hand, I guess I didn't want to scare him off if he made something on the flop I could beat (we shall call this "mistake #1").

The flop comes Ac 4c 7d, he checks, I push and he calls w/ As 9c. I fail to improve and am out in 6th place. Was this push wrong? With as much in the pot as in my stack and the blinds/antes so high, I don't like my chances of winning the tourney from the short stack and, as nothing but 1st paid, there was really no incentive to sneak up a spot or two. Again, the more I think about this, the more I believe that, since I was going to push with an ace on the flop, I should've pushed preflop (though I suspect he would have called with A9 anyway; not that that makes a difference now). Thoughts?