S.F.
I've had my tempur-pedic, with the mattress protector, for over ten years now. Fluid of all varieties invariably wind up on one's mattress, despite our best efforts. The $80 is money well spent to protect a very expensive mattress.
As for "too hot," I don't find my bed to be so, but I tend to run cold. My husband, who tends to run hot, has never complained either. We simply adjust the bedding to match the season and go with it.
Good luck!