Currently there are 9844 quests in the quest database, but this includes daily quests and both Horde and Alliance quests.
Alliance has 2521 quests, Horde has 2493 quests. 2674 quests are available to both factions. This tally does not keep into account class-specific quests or quests that have been made unavailable to players but are technically still in the game.
Kill stuff, do quests and chat
Go to the outlands
The best way is to complete as many quests as possible and by killing as many mobs as you can whilst you do it.
Yes, World of Warcraft is violent - but the violence is not explicit and it not the only thing in the game - there are quests and professions that are not violent.
You get experience by either killing monsters or doing quests.
You must do a lot of quests and go to Raids and Dungeons!
As of Patch 3.1 of World of Warcraft, there are no longer any "daily" quests in Wintergrasp. They've been moved to being "weekly" quests. There's a lot of information about the quests in Wintergrasp, including the random weekly quest players will want to hunt down. See the link to WoWWiki's page on Wintergrasp Quests to get the full deal.
I would say a similar game to Habbo Hotel but has quests would be World of Warcraft.
Humanoids drop gold when killed, and it can also be obtained from chests and quests.
Probably do daily quests or heroic instances :)
You need to be level 70, and have your epic flying training.