I've read the Level 70 Tanking (http://thedruidsgrove.org/wow/forums/showthread.php?p=145281) thread. But seeing that I don't have mangle or lacerate. How do I tank with just Maul, Swipe, Demo, Enrage, Growl and FFF? Should I avoid Maul even on single targets?

During solo PvE quests with multiple mobs, should I Maul one mob down at a time, or use swipe? Which has rage efficiency in this scenario?

If you only have Maul, use it. Just not on every swing, if you do not have enough rage.

When doing solo quests with 2 or more mobs you really should have no rage issues and can use Maul all the time. You should focus on one target and try to CC the other(s) - root them, stun them, whatever.

I often started in Cat Form and, out of stealth, built up 5 CP on one mob, Maim, shift out, throw some heals, go to Bear, finish them. But that only works when they do not hit hard.