I cannot confirm for the SD but most bikes the clutch switch allows you to start the bike in gear with the clutch pulled in, with out it I am pretty sure you can only start it in nuetral, which to be fair is what most of start the bike in anyway.
Yes you can take it out but as Klinck mentions it will start in gear. Man... Aaron you're on a mission! I didn't think there was much to gain from the wiring harness as the wires are already thin as. But I guess you take all the surpluss wiring for the indicators and so out, still.
You have a light weight battery in there I assume?