[bigpooch]

Hand 1: a couple bad things about trying to semibluff in
this spot:
a) the big stack is in the big blind
b) your semibluffing hand only has one high card
c) you have a small pair (making it a tiny bit more likely
someone in the blinds will have a legitimate hand)

Now that you did risk the semibluff and caught an offsuit
ace, why did you bet? Don't you know your hand has some
showdown value? It is possible that the big blind also has
a busted draw and AK-high is a decent hand against a bust.

Hand 2: Reraising is normal since this is limit. After you
simply cold call, calling the river bet is normal.

Hand 3: The only way you could get away is folding to the
reraise, but seeing you are short-stacked, you would have
to weigh your chances that you'll win with this hand (as you
are pot-comitted) versus surviving the blinds. You would
have to get somebody to make a careful calculation to see
when you can fold to the 3-bet and I won't be surprised if
you are forced to commit your chips on this hand.