So, I play tournaments for fun. I'm ok, but I think I play way too tight.

So I made it deep in the PokerStars $10 rebuy last night. I was in the top 50 for most of the night. Unfortunately, I was really card dead after the rebuy period and was playing super duper tight.

My questions:

With about 150 people left, I folded KQs twice when shorter stacks (with Ms around 5-8 or so)with just over half of my stack pushed all-in ahead of me. Is calling an all-in for half your stack late in a MTT to a shortstack a bad play?

Also, about that same time (I had around an average stack), I folded AJo from UTG. too weak?

Also, I got knocked out with I pushed from EP with an M of around 5 ( I think I had about 12 BBs left) and got SNAP called by 88. He had about twice as much as me, so he called off half his stack with 88. Is that a good play? Is that something I should be doing?

KQs thing is not specific enough.