2/2 does sound extreme. Unless there are some really tight 1 gear corners on the track.
The general tried and true method for ZX10R racers in Oz seems to favour -1/+2 (-1/+3) depending on track. This works well for Wanneroo Raceway in the West (only hitting 5th gear on the long straight) and also Phillip Island where the long straight simply means you get to use 6th.
I have been told before to avoid going more than -1 on the front as the size of the front sprocket is now starting to get quite small, forcing the chain to start making a more rapid change in direction, this starts to put extra strain/load on the chain which starts to take up horse power...
The fact behind that claim I have yet to witness first hand but if anyone wants to give it a shot on the dyno, compare a -2/+1, to a -1/+4 and post the results.