Grinding is mind numbingly boring and you will start developing repetitive strain injury relatively quick ;)
Questing will get you gear, rep, gold, flight paths and a tour of the virtual world you play in.

If I were to start on a new server I don't see how anything except questing would work. I wouldn't start looting until level 50ish, you will have plenty of money from quests to get mounts(with raf you will be late getting mounts but that is a problem no matter how you level) and no reason to hit the auction hall ever. I wouldn't bother with any professions at all until the level cap. This will get you a basic set of level 80 characters in no time which will give you a large amount of gold doing dailies so you can quickly power level any professions you want.

If I were to start boxing on a server I have a good boosting class at 80 I would probably instance boost to 60. If you are doing 5 or more new characters the answer is still questing.