No.

EVs are more efficient than the low range for the motorcycle. If you charged your EV with a portable gas generator, your efficiency is comparable to an ICE motorcycle. Most grids at this point are quite a bit less CO2 intense than a personal generator. That cuts significantly on the CO2 impact.

The only upside to a motorcycle is the reduced energy requirements for manufacturing. But lifetime, an EV will be the clear winner.

Pretty hard to guestimate as it's anywhere from bike efficiency to more than ev efficiency.

What makes it hard is capacity. A fully packed electric train will be the most efficient transport mechanism. A mostly empty fossil fuel train can be as bad or worse than ICE vehicles.

If you have one available, then it's probably your best bet to lowering impact.

In terms of distance over energy? Damn right.

Yup, this is perhaps surprising to some.

Bikes win hands down by being the most efficient form of energy usage for transport. Walking requires a lot more calories to travel the same distance you can go on a bike. Those calories come from farming and that (diet dependent) very quickly can outpace any lifetime savings from using a bike. A bike is about ~99% efficient at converting energy into motion.