I'm thinking your talking about the Cowdry profiles stuff, which I've never used. The size of your waxes compared to post-cast depends alot on your techinique. WHen I was steam casting, I would carve a size 10 ring at a size 10 wax, and the shrinkage was small enough that during finishing, you would take it down to a perfect 10. Now that I'm vacuum casting, I find I have to make the wax for a size 10 ring alkmost a full 10.5. I have never tried centrifugal, so I don't know about that...
Probably the best thing to do, is get some of the wax you mentioned, and just take measurements before and after a cast. You can always grind/sand a little of the metal off after the cast if you need to, and it can always be soldered onto other silver.
Just remember, always try to mix a minimum of 50/50 already cast silver with virgin silver, and you can't cast silver that has solder on it.
Wish I could have been more help on the bezel tape. This is something I plan to get more into myself, in the near future.