The sidestand relay works together with the switch on the clutchlever and the diode. All to do with starting and preventing you to take off with the sidestand down.
I would NOT delete the decompression solenoid as this is for easy starting the big thumper. Some people I 've heard make the decompression manual and use it for starting and killing the engine.
The turn signals and relay can be remove all together if law permits.
A wiring diagram will help you to do this.
Keep us posted
Greetz
Kropatchek