Used PT license and my Avid account

[Analog Kid]

Hello, I have a bit of an unusual question. I purchased a used copy of Pro Tools 12 from eBay. The seller provided me with the login credentials to the iLok account that the license is activated on (and I immediately changed the password). So far, everything looks fine - the licenses are in the account. However, the seller will not do a transfer of ownership. Because of that, I have a few questions:

1. What would happen if I revoke Avid's access to this iLok account, sync the iLok account to my Avid account, and then re-grant Avid access to the iLok account?
2. Have I just purchased a license that can never be updated?
3. Does this sound like a sale that's not legit (the seller seems to have sold various other PT licenses, as well as other pro audio gear, and has 100% feedback)?
4. Am I hosed?

Thanks in advance,

The Kid