Kick ass climb it sure was Tweezer. Goes down as one of the more memorable adventures in the hills as you really have to earn it with all the quick elevation gain/loss and the exposure factor on the traverse and at the block.
As far as the rating goes for the FT, I'd say it's probably right on. Though there is certainly a fair bit of exposure which is easy to get spooked on, there are PLENTY of places to put your hands, and foot positioning is relatively straightforward. To be honest, I thought the last couple moves at the summit block were more menacing to downclimb with a pack on than crossing at the finger traverse. (Though I'd suggest leaving your axe at home... mine kept getting caught on the overhanging rock above my pack)
Regarding route finding, there are a few cairns erected in spots where it makes sense. It's easy to start shooting up the wrong rock gully when you are nearing the summit, but it doesn't take long to discover the true path.