lol...well if you get bored as heck doing instances like I was then do all quests for awhile. But I basically did all instances as soon as I could. I stopped at Uldaman then started doing quest out of boredom. Then my last was Sunken Temple for the experience plus I wanted that trinket you get for the Shamans. And oh was that a trip, dealing with multiple mobs at once. Scarlet Monestery gave me alot of experience as well in how to deal with multiple mobs. All in all, quests of any kind do not give you the experience you will need for harder instances.

PVP though will always occur while doing quests. The only times I ever die is because of ?? higher level players ganking my group. If your into keeping track of those gankers...then get "OPIUM" addon. I love that program. I can always go back to see who PKed me and then look them up in the armory later to see what level they are.