I think you have to play under the assumption that AA usually wins but is one pair and only one pair so need to protect it. Sure play games with "ck and go", ck/raise etc. but your just looking to get donked like that. Personally I like AA heads up all in pre flop if I can offer it - hopefully they fold their big pre flop raise - if not your prolly 80% plus. problem is - if its very ealry in a tourney and you dont want to get railed you may want to play slower and feel them out but youy have to rasie pre flop no mwtter what - specially in a free roll. They will instantly think you are bluffing and call you down if you do anything else. This is gd most time but early on you dont want a war just a battle for 30% of your stack max.