235/65-16 or 255/60-16 are acceptable swaps.
That is a fairly good swap. Know that your speedometer will show 60.8 mph at a true 60 mph. A better swap would be a 265/70-16. Your speedometer would show 59.7 at a true 60 mph.
You can but know that your speedometer will read 59.2 at a true 60 mph. This is a decent swap but I always recommend you stick with the OEM size. No real reason to swap sizes.
Yes, this is an acceptable swap as there is only 1% difference in overall diameter between the 2 sizes.
If the tires are the same size then yes.
No, this is not a good swap as the 215/70-15 is over 3% too small in overall diameter. If you wish to go with 15" wheels then install 235/70-15 tires which will be only 0.36% different than the OEM size.
You can but it is not a good swap. If you are asking can you swap 215/65 for 215/70 series tires know that the 215/65 will be 3.17% smaller in overall diameter and your speedometer will be 2 mph off. If you are asking can you use both sizes at the same time, then yes as long as you keep each size on the same axle. Do not mix them on the same axle.
No, it is not an acceptable swap. The 215/70-16 tire will be 6.47% larger overall diameter. You should never go over or under 3%. No 70 series tire will be an acceptable swap.
Yes, you can but your speedometer will be 1.8 mph to fast. A much better swap would be 225/65-16.
Yes, that is an acceptable swap.
Yes, that is a good swap.
Yes this is an acceptable swap.
Yes, that's a reasonable swap.