Yes with permission from Seller Support and selling different items and with different bank accounts.

Without permission, you will probably be suspended at some point.

More of an issue with Sole Traders than Ltd companies.

Generally Amazon allows one account per household , but like the others here say you can request permission from Amazon for a second account but you would need to give reasons why .

The two accounts as far as I know will not be able to sell in common categories .

Yes you can add user permission, you can go to settings and add user.