I think Rampage is an exception if I recall.
Yeah! Rampage, Gauntlet, and I can think of about five or so others off the top of my head, so there are probably quite a few.... some of the fighters use separate coin inputs too. As do things like several Neo-Geo MVS games.
As for needing a keyboard or not.... debatable point!! I have a keyboard, mostly because it means that I don't have to have lots of admin buttons on the panel. You will need access to things like the TAB key which is used in Mame to get to the options menu and dip settings for games.
It's also very useful to have a keyboard connected when your are setting or altering the software setup of your cab or altering options and setups in windows. You're going to do this much more often than you may think.
It's easy enough to connect a keyboard to the Keywiz. So you should have no problem with that. Plus a keyboard is a really cheap thing to add in there, but will save you a lot of grief later on.
Best Regards,
Julian (Fozzy The Bear)