Check your frame ground which is behind the battery right next to the ECU,and also the ground that is very close to the throttle cable you're going to have to remove a piece of plastic right next to the throttle cable , looking at the starter cable , this ground is about 3 inches left.
Sorry for not giving a professional answer, I am a master electrician with electronic endorsement , and a motor shop background . First starting out I was given stuff nobody else could fix, pretty much continued like that for the next 35 years. I thought it was impossible for one person to have that much go wrong , and thought it was made up by someone that was recently kicked off this site.Nice thing about this site is you can always go back and edit
I think you may be mistaken about your headlight relay, look under burnt stators, I have some extensive tests to prove what needs replacing.
FYI. Slow down in replacing stuff, unless you have lots of money, always best to prove what is wrong, then replace. Easy to cause damage with adding parts that are installed incorrectly.
First thing I would do is disconnect the stator at the TPS sensor, measure the 3 phase voltage at idle coming from the stator, A-B , B-C, C-A, should be around 20 volts AC @ 1400 RPM , give or take a volt.
To check headlight relay, turn key to on, no need to start bike, same connector but socket that continues to regulator, take a jumper wire from positive terminal and touch any one of these three wires, one of the three goes to a diode and the relay, check each one, one of them should pull the relay in, once pulled in the relay latches-------in other words if your bike was running and you stalled it, the headlight would remain on, however initial starting, the headlight is out of the circuit until the stator starts to produce power to reduce load on the battery.