FI light comes on after disabling the clutch switch?

The clutch switch must be operational. The bike uses this for other items in addition to starting. We also know that removing or disabling the clutch switch will create a false (early) rev limiter on the 2008 Hayabusa and all GSX-R1000's. Modern bikes are sophisticated and a simple switch may have many tasks when it comes to the proper operation of the bike's engine management system.