Currently in Mists of Pandaria, the latest expansion to World of Warcraft, there are 90 levels.
Yes, a level 52 is able to get into Sunken Temple in World of Warcraft.
One can purchase max level World of Warcraft accounts from a site that offers the services of selling World of Warcraft accounts. One example includes "BuyMMOAccounts".
25
A level 60 raid.
?? boss
The best way is to complete as many quests as possible and by killing as many mobs as you can whilst you do it.
wetlands
Level 14
Level 65 is required in order to obtain and use the gunblade on World of Warcraft. The gunblade is dropped by monsters whom are in the mid-65 level range.
Tanaris
Outlands..Hellfire Peninsula
Incinerate can be learned at level 64.