[AtticusFinch]

Honestly, I don't see how question 2 is necessary. How can you answer question 1 without first answering question 2?

I've said all along that our play looks exactly like a made straight. The only other hand that seems likely from our line is AQ. As Adanthar said, we'd have to be nuts to play a set or overpair this way, and I presume that at this point villain's read of us at least concludes that we're not that crazy.

Here's a hand villain could easily have called the turn with but might still lay down on the river: a set. Sure, he was only getting 2/1 vs 3.6/1 odds for filling up, but sets are hard to lay down, and he could have called based on some implied odds from the rest of our stack, and a lack of complete confidence in his read. His hesitation smells exactly like, "Damn, that bastard made his straight. Can I call?" Other possibilities are a pair with a jack (especially QJ), or something like 78c.

In the low-buyin tourneys I play, I check behind, because I can't credit those players with the ability to lay down a set, or even two pair, EVER. And TPTK, maybe once in a blue moon, but not often.

But here, in a 10k buyin, against a solid opponent, I'd be inclined to push. Villain is far from dead if he calls and loses, but he sure won't be happy. Of course, a more detailed read would come into play, but absent other information, I'm pulling the trigger.