1) Cash is passe -- I only use it for vending machines. Check is becoming so. Unfortunately, almost no pizza place around here takes cards, so I use check. Haven't been turned down yet.
I don't eat Domino's, though. The politics don't bother me, but the pizza is disgusting. Since he's sold the chain, I doubt I'll try it again (and that's as close as I'll get to that).
2) My tips usually amount to a buck or two. More in the "keep the change" category (unless the weather sucks). I used to work at a Pizza Hut, and did delivery, waiting tables, and cooking at various times. The drivers have the easiest job and make almost as much base money as the management. On top of that, they get money for each delivery (10 years ago, it was $.50) from the company.
Even as a driver, I always thought the idea of tipping was pretty thin. A job a poorly trained monkey could do and the highest "staff" pay in the store.
Oh, yeah! Almost forgot (actually, I did, so I'm editing):
Papa John's is the best delivery chain. About the only better pizza comes from local places or Happy Joe's, which is just too darned expensive.