The "old" CD key is for you to create an account
The TBC CD key is to upgrade your account to TBC

So to even HAVE an account, you'll need the "old" CD key but you can choose not to have TBC CD key and still be able to play

I've given 2 friends a free trial and they've both upgraded to the normal account, and I've am already using the complimentary 1 month WoW access. One converted about 4-5 months ago while the other converted about 2 months ago.

But yeah, try at your own risk... :b and you'll need a credit card to get the 10 day trial thingie

Could you let us know how you came to conclude that we can use the 10-day trial in malaysia with no issues? Having 2 friends who converted their trial accounts into full accounts with no issues is really not sufficient. I've also recently had a friend convert a trial account into a full account with no problems but many people seem to pinpoint that their accounts got banned because they were using the trial accounts. It could just be that your friends weren't "caught".

But if you do have other supporting documents or information please do tell us, I'm sure many of us are very interested in knowing about it.