I'd drop the points from Brambles to max out Control of Nature and then spend the free point to get another bit of threat reduction via Subtlety. Brambles is... pretty mediocre, to say the least.
What kind of content are you going to be doing as a Boomkin? If it's 25-man raieds you really should get Imp. FF pretty much no matter what. If it's 10-mans and you don't really bring any melee who'd benefit (Enhance Shamans, Rogues, Fury Warriors) then it's another story, though. It does give a rather nice threat boost to most tanks, so if that's an issue I'd reconsider it.
Anyway... try
this for your needs. It's just slightly tweaked but the principle is the same.