Okay. Prior to today, I have been building a barb whose purpose was to be a THF, trying to balance tank and gank.

I had originally looked at Frenzy and thought to myself "This is simply Vicious by another name. Since I swing a single big weapon, I'm not going to get as much mileage from this as a TWF would, and I'd rather spend my points on brute fighting, improving my power attack, and improving my toughness/constitution."

Glancing at the other thread, "Is Frenzied a must?" it seems that I've clearly misunderstood either what Vicious does, or what the mechanic behind Frenzied is altogether. Since the in-game description is...well... inconclusive, and the out-of-game materials I've been able to locate on the discussion are also inadequate, I throw myself to the mercy of the veterans who, in the past, have outdone themselves helping me.

Please spare me the smartass flame answers - I freely admit I have no idea about this, I have sought out the info, and the compendium is less than ideal.

1. What exactly does FB 1/2/3 do/enable?
2. Why is it so massively important? My DPS at level 14 certainly seems more than potent as it is?
3. Is the HP drain you get from running the ability significant enough to be a problem, or is the extra damage you do always worth it?
4. Is it appropriate for a barbarian who tends to tank for his friends, as I do, or strictly for a damage platform?

Thanks in advance as always. My barbarian is a Warforged, if that matters.