bear in mind that there are many out there on markee who have more experience when it comes to these matters, so don't limit yourself to asking for an individual's advice : )
as for your question. while there is no set period where an account transfer can become unreversable (i have tried restoring an account transfer 6 months later for a friend), there are ways to make it more or a hassle and difficult for the would be recaller.
let me briefly outline them:
1) transfer your character off to another account with a similar last name - obviously, change the secret answer to something only you know (keep all CD-Keys for future reference etc...) <-- you have already done this step.
2) pay for the new account ONLY using gamecards (sometimes, blizzard will refuse to recall the account for you on the basis that the subscriber had a different name (credit card) than the account registered name).
3) one your character is safely sitting on (the recaller or transfer reverse guy needs to provide such information on the webform to sucessfully recall an account or reverse a transfer)
a) new account
b) new server
c) different name
4) now, call blizzard via their account management hotline from 8 am to 8pm pacific standard time and ask to change the email address and reset the password for your ORIGINAL account.
the blizzard representative will ask you for the following:
a) registered first and last name
b) secret answer
once this has been validated, request that they chnage the account email to an alternative email address you can access (DO NOT USE THE SAME EMAIL AS YOUR NEW ACCOUNT - as this is calling for a ban) --> get them to repeat and spell out the email address you provided.
now ask the representative to reset the password (this will be generated and sent to your email within 10 mins) --> DO NOT hang up until you have it and can login.
5) now repeat this step of calling up blizzard and requested account information change 3-5 times in the next day or so. your original account will now be locked for compromisation <-- this is good.
6) now in order for the original owner the reverse the transfer, he must first
a) call up blizzard
b) fax in his NOTORIZED goverment issue ID
c) file an unauthorized transfer webclaim
d) process the claim
e) engage in an account dispute with you on your new account
you are advantaged cause you have recorded down the following which you can provide to blizzard to prove original ownership:
a) CD-KEYS
b) ALL used gamecard codes --> keep a history
c) ALL passwords ever used
d) ALL emails ever used
e) ALL character information on the account (name, level, server, gender, race etc...)
seeing that there is NO WAY the original owner can get access to this information, you have secured the account and won ownership (he will be left with a blank dummy)
note that most people will not bother after they have recalled their now locked / banned account!
Good luck securing your account(s) - contact me for help / questions : )
-Bones
