More World of Warcraft Questions?

I need to Know Every thing before i Buy the Battle Chest First does it cost 20 dollars to activate the account and if it does that would go on my Battle.net account right other than that i know how to pay for EVERY THING. Second I want to play Draenei what should i go with Palidan Or Mage i really like to use magic but mages can use portals to capital citys and do other useful things use frost arcane and fire but can only wear Cloth btw i like wearing heavy armor yet i dont like warriors cause theirs no magic Palidans can wear mail and plate and heal them and their party members and play tank but cant use magic like mages they only use holy magic. Third your opinions Horde or Alliance thanx for the answers