Rax,
This is just me, but I try to avoid the rebuy tournaments to begin with. Most of these are basically who has enough cash to outlast to the last rebuy/addon period. Kind of like Poker Survivor!
But if you have to play them here is how I play them. Granted there are many more experienced players on here but I thought I would give you my opinion on it.
I would be playing only premium
hands and play tight. It's kind of like the thread on the aggressive player. Not much you can do with these people unless you have the nuts. there are so many more suck outs in these tournies than regular freezeouts IMHO. My plan when I have played these type of tournaments is to hold my own and rebuy/addon right before that period is up. Of course like any other tournaments the more chips you can accumualate before the end of the rebuy period is always helpful. Basically like any hand you want the Best Hand going in. I would take advantage of when I saw a real chance to limp or even small raise a lower premium hand in late position like your mid PPs. I guess I am just rambling here so.
I haven't played one since I think the last cardschats freeroll/rebuy we had late spring early summer last year. So I'll leave the rest of the comments for the ones that do play these.
I hope I was some help Rax.