No.
no if he has a permit
The SKS is not an assault rifle, nor even a BATFE-defined "civilian assault weapon". And no, a permit is not required.
Yes, once you've obtained an NFA permit for it.
No
No.
Without requiring an NFA permit, the largest bore weapon a civilian can own is .50 calibre/12.7 millimetre in the US. Anything with a larger bore requires an NFA Destructive Device permit.
In MOST of the US, a permit is NOT required to purchase a .22 rifle. IF one is required in your area, it is because elected politicians passed a law that says you need a permit. You would need to ask them why they did that.
Yes
No. Minnesota requires a transfer permit for handguns.
Depends on situation, but usually yes. However, failure to make arrangements to pay will find you in jail for contempt, which does not permit rifles.
Depends on the laws where you are.
Get an NFA Class II permit for one.