Will these wheels fit with the 38 offset? What about with 215/40/17 tires? Probably will fit with 205/45/17, but I'm not sure.

I know MSFITOY has these rims in 45 offset, but added spacers to make them 40. Also he runs 215/40/17's. Will an extra 2 millimeters make that much of a difference?

My car is not lowered, although I may want to a little in the future>or maybe not...

These are the wheels I'm talking about on edgeracing.com

http://www.edgeracing.com/2002/Mini/Cooper_(all)/wheel/94/

 

Really depends on which tire you use with such minimal space left.
I would suggest a 205/45/17...

Is your car lowered? If not, they might fit and rub a tad when you hit a
big bump.

 

It depends on the section width of the tire,
I run 225/45 r 15 on et 35 rims with rubbing on the outside.

I think you combo will be just about perfect with et 38.
There area you are going to have to look at is on the rear trailing arm.