PS20/180 - ITM, help playing this hand

[CA02]

I was playing a 20/180 last night and was wondering how you would play the following hand. Blinds are 300/600/75. We are already in the money with 17 people left (9 on my table). I am BB w/7000 after posting BB and ante. I am one of the short stacks (prob around 15th place). UTG (t18,000) raises to 1800, folds around to a MP player (t43,000 - the large stack), who goes all-in. Folds back to me.

1. First question, what kind of hand would you play against this action?
2. Second question (related to first), what kind of hand ranges do you put these guys on?

Okay, hope you thought up the hand ranges, so I will now complete the story: I called the first all-in with AKs. UTG called the all-in with AQo and MP had JJ.

3. Third question: if you knew that large stack went all-in w/JJ would you still call with the AKs?