Adsense doesnot allow multiple accounts. There is an every chance to get banned. If you are able to delete one, do like that. Else, do not use one of your adsense account( in the same pc, router, location).
You cannot change your name from adsense account. It is permanent. Better change your address of contact and all other details.
That is possible. But if you're caught, then you're dead. Just Kidding. If those accounts have different payee name and address, then you're fine. But if not, you should be deleting one of your GOOGLE accounts. Not just in Adsense but also other accounts for you t be 100% safe. Good luck!
Contact Google and explain the situation to them. If you try to hide it and they find you they'll ban you.
I recommend u to delete your one adsense account as Google does not allow multiple accounts and there are chances of both accounts getting banned so its better to be safe with one account.
Having two adsense accounts is simply not acceptable by Google. They have a very stroing tracking mechanism and if detected, your both accounts will be under the risk of getting banned.