free roles are a donks best friend, it will be a luck grind and if you get lucky you will win a small ammount of money...
unless its an organized freeroll then you get to play some real poker
also most freerolls are 5-8 minute blinds, so you have very little play time to gain your lead
as for the low stake tourneys, you will get your people donking you, and i sometimes feel if there is more then 100 people its not always worth it cus guarenteed you will get sucked out on a lot,
with around 80 people in it, then 2 races later on should find you on a final table, so as long as your playing your % correctly and not allowing yourself to fall below 10bb then you should do fine
as the stakes get higher the play increases and you can start using more advanced techniques but i find anything below $5 buy in you can get to a final table with standard ABC poker