My guess is that they will work just fine! Most distros will work equally well once set up, but some may require an extra step or two for driver installation. From what I’ve seen, Mint is a good starting point overall and is what I’m recommending to friends right now who are using Linux for the first time :)

I would say that 90 F won’t be a problem on an ebike, since you can rely a lot on the motor, and you have air flowing all around you. I mostly use a regular bike but then I just bring a spare t-shirt.

I would rather say that I don’t like biking when it’s below 35 F. Still doable, but not having to deal with that it should be really nice for you :)

Max allowed speed for ebikes on bikelanes varies but should be about 20 mph if you’re using only the motor.