Yes, you can
Yes, they can
no
Yes, they can
No, your speedometer will be 3 mph too slow. A 205/60-15 will be a good substitute with almost no difference in overall diameter.
Yes, that is a pretty good substitute.
Normally. yes.
Yes, you can
Yes, this is an excellent substitute.
Your best choices are 205 60 r15.
no there is too much height difference
Sure, if you change all four; the difference is about a quarter of an inch in diamater.