So I've started commuting by bike, in NYC

[sir pball]

3. There are rules of the road for cyclists

At least here in NYC, we're technically motor vehicles. To be fair I have a bit of a flexible view of the law on both a moto and a cycle (e.g. filtering/lane splitting, squeezing by on the shoulder, MAYBE ignoring a red late at night after a full stop and check, stop-sign style), but "salmoning" (riding against), sidewalk riding, blowing lights, diagonally crossing intersections, no no no.

I'm not sure I'd favor licensing, only insomuch as a lot of very poor folk only have a crappy bike and even a $50 license would be a time and money burden, but knowing the rules and more importantly knowing how to survive are definitely important.