You can use a cap without a resistor.
The coil will supply whatever voltage is required to jump the spark plug gap (within reason). The resistor won't reduce the spark intensity.
Fork oil is compatible with mineral oil. Brake fluid is not compatible.
Take a 2" section of a handle bar, bolt it to the back of the headlight. Attach the switch pod to it.
Yes. Air in the system or failed master cylinder seals.
You can take a syringe and force fluid into the slave cylinder. You would see bubbles coming up into the master cylinder.
I don't think that the Fantic's engine has enough Yamaha parts for them to restrict sales in the U.S.
I may be wrong.
The Fantic has been keeping me up at night. But, the Rieju 300I will be a lot cheaper.