This is probably a dumb question but, with alot of guy's galvanizing the frame,
a-arms, control arms etc.... why couldn't the SS wheels be galvanized? I'm
probably missing something but, I thought it would be great not to have to
worry about them rusting!

with a good quality paint you wont have to worry about anything rusting on these cars again.
because they are no longer driven in Bad Weather

I plan on driving mine in any weather...

I would not galvanize the wheels mainly because when they do it it might have too much clag buildup in one area and will cause your wheel to be off balance. I galvanized my 69 vert frame and a few other parts with it but not my wheels. Plus on the inside of your wheels their is a small rim and it and if you did get them galvanized it will fill it and look bad. JMO

How thick is the coating when you get something galvanized?

Its very thin but very easy for them to get it too thick in other areas also I would not take a chance on the wheels.

You might want to think about powdercoating. I did it on my SS rims.
I had them powdercoated silver and then painted the black.

Thats a thought... Can they coat them in the correct color?