You shouldn't be looking to risk your tournament life to scoop up someones starting stack.
You want to just play it as normal. Raise and then evaluate every street.
It depends on what you know about the players on the table. If it is mostly aggressive players; you limp, if passive players, you raise.
Aces first hand, UTG, MTT.
What will you do?
Just a random question that came to my mind.
Chipsteal_
Raise 3BBs.
Pushing all in screams AA, KK, or AK, but in freerolls you might still get 1, 2 ,3 or more callers.
Just happened to me on the first hand of a freeroll. QQ raised 3BB. 86s pushed. I called with JJ. Some other rainbow hand called. Four all-in players first hand. I hit a set and won. The quality of your cards is almost irrelevant with 3 to 4 all-in players pre-flop.