You can not take away time from your World of Warcraft Battlenet account once it has been added.
You don't need to you just use your battle my account name and it merges for you.
Yes, you use your Battle.net account to log into World of Warcraft.
No. You still need to pay to play.
This question makes no sence.
By going to the Battle.net website relevant to your country and registering an account.
No, you can not have more than one battlenet account on one licence of World of Warcraft. You can however, have more than one licence of World of Warcraft on each battlenet account.
2 reasons. 1 you didnt install it or 2 you dont have a battlenet account
Your account can be merged once with BattleNet. Different accounts need to get merged separately. If you're talking about transfering your characters to another account or server, you can do so as much as you want but you still must pay the $25.00 USD.
It seems that Blizzard (the makers of World of Warcraft) has implemented paid Race Changes. Go to your battlenet account management page to check it out under paid services. The cost is $25.00 per character.
A Yahoo e-mail account is free .
Probably, if you have a battle dot net account they could ban that if you are found to be connecting to a private server.