So, just a few comments. Some of your justifications are not valid.
-Motorcycles are not automatically cheaper on gas. Both of our bikes use more gas on a per 100KM basis than either of our vehicles.
-The increased cost of insurance (I hope you realize at your age and experience level that's going to be VERY costly) will eat up any possible savings on gas vs inside a month.
- A motorcycle is not a 12 month a year transportation solution in Ontario, but insurance is a 12 month commitment. Next November through April/May what's your transportation solution, remembering that you'll still be paying insurance on the bike?
Now, that having been said, if you are as financially independent as you say you are, then none of those should be show stoppers.
But, are you as financially independent as you think you are? It sounds like you have never lived on your own, and from all of us who remember moving out on their own, well...it'll cost more than you think. Have you drawn up a budget that's realistic? How much disposable income do you have left every month after all the bills? Mortgage/rent, condo fees, groceries, payments on your furniture/appliances, electricity if not included, internet, cellphone, etc?
I know none of the above is really any of our business, but IMHO I would suggest living on your own for at least a few months before jumping into ownership with ANY vehicle, much less a motorcycle.
As for your family issues, you're an adult. Make your own decisions. Your family may not like it, but a time comes when decisions are no longer theirs to make once you've moved out from under their roof....that last bit being the key. Their hissy fits seem incredibly childish to me, but that's another story.