Hey villain, I am also playing a great deal of those freerolls and i find myself in the same position often. I agree that most of the players once you get to the final 25 or so are pretty solid, but the thing is, its hard to get them to fold. That is what makes freerolls so hard, you are basically gambling or just trying to get lucky, which doesnt help. I have placed in about 10 of the 100 or so of those freerolls ive played, I find that its best to just steal the blinds when given a chance and dont take any unnecessary risks w all your chips. Its good to try to steal the blinds against smaller/weaker stacks that are trying to sneak into the money. Avoid getting into too many hands when you are playing against the larger stacks because they will call with almost any live cards.
I was playing 2 days ago and there were 12 left in that freeroll, I pushed w AKo preflop, hoping to take the blinds no problem. I got called w J8suited, and boink, villain hit his 8. Left me losing w 12 left when 10 get paid. I wasnt happy about this situation but there wasnt much i could do. I had to try to take the blinds as i was low stack, but i knew that i would probably face a call from a big stack w almost any 2 cards.
Basically, you want to be more selective in your position/people you play against. Don't worry too much about your starting hands w what you open, but instead focus on THEIR chipstacks, and YOUR position. This should help you to slide into the final table where you can pick your spots w some good starting hands. Good luck, and btw, shoot me a PM w your screen name and i'll try to chat w you in some of those freerolls. Mine is SUBDYLZEP. Hope to see you on the final table.