Personally, i would tell them to avoid the quests, as they give too much exp and far too little rewards. Whilst exp is not a "bad" thing, you might as well just do more of what you're doing (more CC/Arena if valour or more mobs to hunt if just playing around) So i would set them along the lines of both, mob hunting to gain some gold and items. CC + arena to see if they enjoy it and if they decide that is what they want to do. The main quest i would push them towards doing would be Experimental A...