Quattro wheel Diameter?

["Robert Lester" <lester@cyberportal.net>]

Hey guys, my 90 80Q needs new tires this week...(story-was rotating tires
yesterday,back right tire inside worn down to steel!...info...they are
summer directional tires, all but the back left tire seems to be
worn/cupping inside&outside tread, does this mean too heavy turning? I blew
up and mounted the spare on the back right, until I get new set of four.)
1. why is the spare a 15" rim, when I have 14" BBS stock rims?
2. Isn't it bad to have all four wheel diameter's not be the same?
3. Looking at TIRE RACKS Firestone Winterfire (winter) tires $48
ea.,195/60R14...suppose to me ok grip? quieter? speed rated 118 mph? Any
thoughts apprec?
4. Do all disc/rotors spin so the wheel lug wholes don't line up, or did
someone put on a less expensive set of rotors at one time? (only on rear I
think)
5. why can't I go to a cushier size tire for the winter? maybe 195/65R14?
or 205/60R14?
TIA Bob
90 80Q (Nologies/amp)