A convicted felon may not purchase, possess, or have access to firearms ANYWHERE in the United States as per federal law.
You need to consult with a lawyer familiar with firearms law.
NoANS2:In the US, there isn't anything prohibiting your neighbor from selling you a shotgun if you are not under disability (i.e., a convicted felon, mentally deficient, drug addict, etc.)
NO
A felon cannot legally purchase a shotgun anywhere in the U.S. unless the felon's rights have been restored.
Not legally.
Yes...
No. A convicted felon is a convicted felon regardless of WHERE they go or live in the US. Note: Use caution if you're even thinking about it! The federal punishment for felon in possession of a firearm is a minimum of 15 years in federal prison.
No.....
YES
Provided you are not a convicted felon, you can buy long guns at 18 and hand guns at 21.
Yes. The second amendment says you can do that. The state is allowed to impose reasonable restrictions on things like the length of the barrel and to restrict the possession of firearms by people who have been previously convicted of certain crimes, but assuming you mean a normal, unmodified shotgun and aren't a felon, then yes.
Getting a mortgage loan will be the problem, not the purchase. If you pay cash, then there is no legal reason that will stop you.