Is there any way to secure this account?

Alright, I bought an account, a former members account. I wasn't given any member info, but the info that was given, can recover the account even with recoveries on. It just takes them a longer time because they actually have to read it. Now, my dilemma is that once I pay for it, it's possible to be taken back by the owner because of the info that has been given to me, and also the chance he may have old member info. Honestly, I think he does, but there's the chance. If I add members to it, btw the only way to pay is pay by cash, don't ask, but will having that agreement or whatever number be enough? Or will it just go through recoveries back and forth if he tries to take back the account?

 

theres no way for it to be truly safe to buy a account

 

..ok, so what's the best thing I can do for this one?