Clutch switch, I've disconnected mine and it's made no difference at all.
BMC air filter, I used the whole thing and with a full Akro system and power commander it's putting out about 119bhp, not sure if you didn't include the funnel that it'd make much difference. It's there for a reason so I used it.
The exhuast sensor, I've still got it on mine and the guys at Mistral Performance recommeded I used it, can't remember the real name for it and have a feeling if I could I couldn't spell it. With the Akro system it was a bit of a stretch as the cable is a little short. I tried to redirect the wiring but everything is so tight I had to just take up the tiny amount of slack there was and make it fit by less than a flee's cock. Some people remove it but I'm not technically minded enough to give you a definitive answer; I just ride the fucking things...not as well as I'd like! Try calling Seton Tuning, they're experts in R6's and very helpful. Worth getting a set of carbon tank protectors from them, the CSS use them and they've saved their bikes from going up in flames after an off on more than one occassion.
http://www.seton-tuning.co.uk/
Edited: 22/02/2008 at 00:33