I was more concerned with the danger of using bicycle components at motorcycle speeds, torques etc.
Even if you upgrade, reinforce, overbuild every component ... you'll, likely, not come close to the strength or durability of an old motorcycle carcass.
And
An over built bicycle is only as strong as its weakest component ... don't overlook anything!

But, it is a good point that an eMotorcycle has tags and registration and most importantly insurance!
Insurance ... why?
Hit someone with a hopped up monster eBike and you will face legal and possibly criminal liabilities.
Much better idea to have a legally insured motor vehicle!!!