I have the same problem although I did manage 750,000,000 on Mean Machines on Slam Tilt which got me 3rd place but yes it doesnt save permantly although im running it through winuae as my pc monitors bigger than my amiga one so it looks better.
Saying that when it goes into hires mode when you have multiple balls it goes all jerky for some reason.
For the tables I think you have to push space a couple of times or the left mouse button, something like that, hitting it once brings up a credits screen, do it again and it swaps and now F1 and F2 are the other 2 tables million dollar game show and a graveyard one or something similar?