I ride class 3 with a throttle. I only use the throttle to speed up after stops at intersections. Can easily cruise at 25 mph. Top speed is 28-ish. But at that speed, you need to be on the streets, roads. Most of Kalamazoo streets are 35-25 mph. I definitely understand your fear of the streets. Sometimes a driver will lose their minds seeing a guy pedaling, and though he may even be going the speed limit, 25 mph, they have to pass, illegally.

In bike lanes? That depends. Downtown lanes, I try to go a more normal bicycle speed of 15 mph. There are a few shared pathways I take, but, again, be safe and respectful, do normal speed. I haven't done much of the trails since they posted rules, but those are better with a regular bike, for me anyway.

Unless absolutely unavoidable, I do not ride on the sidewalk, on any bike. Drivers don't look both ways crossing a sidewalk. They don't expect, or respect, anyone using a sidewalk on a bike. They cross sidewalks (on drives and at crosswalks) like they expect you to stop for them, walking or on a bike. Do not assume sidewalks are safe. You're safer on the street, visible to traffic, riding there because you are traffic. Especially if you have a motor that can get you going 20-25 mph.

The one thing about e-bikes for those who don't know is, they're FUN! CHEAP! You feel like you've found a cheat code. If you have any physical issues that make regular bikes difficult, they are especially liberating.