FF XIV Player, New to WoW. Tips/Help for beginners?

I have a few max level classes in FFXIV and did a lot of raiding as well. My brother wanted me to give WoW a try, so I bought Warlords of Draenor and a sub. Anyway, I'm enjoying myself so far and wanted to ask some questions and get tips for questing/leveling etc.

-Is there a sprint skill?

-My first dungeon was a bit sub-par as everyone knew what they were doing and rushed through except me. Should I give up on dungeons til I'm a higher level?

-Do you have to be max level to join raids?

-Should I be scared of being a Hunter?

-Is there more customization for the Hotbars? I'm used to having 3 for main skills and 2-4 for mounts and other shit.