So i hoped over to the test sever and tried out a few tests, on that fire giant in the claw.
First off - that silly cleric/wizard/monk mix thing, well it surprised me at how well it can work. I was able to keep tree form up for ~50 seconds from a full 30 spirit. It also generated spirit crazy fast, so fast that I bet you could keep avatar of nature up for more than 50%-75% of the time in quests. Impresive!!
Secondly I toyed around with combat stiles a bit (however not a huge amount). I had all 3 twf feets, The fastest the giant droped was when i didn't have any weapon or armor equiped (centered unarmed attack) - I was able to kill him before tree form wore off. The next fastest was using a starter great sword with no armor equipped. The slowest by far was when i used heavy armor and no weapons. I did not test armed and armored twf as I had no weapons (lvl 21 boat toon).
Perhaps later I will transfer a toon over with equipment.
EDIT: Transfers failed, I have no toons with equipment on lemma and the guide is absent atm.
PS. I think the cleric/wiz/monk would totally rock and as a bonus people would think your a total noob when you joined their party. Think of the hilariousness of it. Of course you would totally suck until you could get primal unlocked.