Reuse old pressure plate or buy new???

If it's in good shape and working right now, no reason you cannot re-use it. A brand new clutch set has to wear in and "find a home" as they say, and your new clutch disc will do the same with your used pressure plate.

Reverse burnouts? Seriously? That's not very smart. The suspension is not made to work that direction.
Not reverse burnouts, get wound up going in reverse and drop it in 2nd then dump the clutch and hang on.