myMiniCooper

I want to replace my stock MCS wheels with a set of 18" (7.5" wide) Team Dynamic Pro 1.2 wheels (flat black). They seem to be the only alternative to the JCW 18" black wheel (a LOT cheaper). A couple of questions though:

1) They seem to be made for "track" use. Any problem using them for the street?

2) They seem to come only in a 30 or 32 offset. I think the MCS needs about 42 for this size. Any thoughts?

Thanks...