Is there a procedure to test the voltage regulator?
Telltale sign for mine was discoloured insulation on the wires coming from the regulator, obviously from overheating.
It seemed to me your bike's symptoms were different from mine. So I was thinking your problems probably were not (just) down to battery/regulator issues.
The rest could have been merely bad fuel tho.
I'm looking forward to hearing how this monster rides ...