Regarding power and speed limits on ebikes, it depends on the local law regarding how they're applied. In AZ, AFAICR, it doesn't matter if the bike is *capable* of more than 20MPH, only whether it is "operated at" more than 20MPH.

Might be similar where you are.
Power limits...well, depending on local laws, you can set a power limit in your controller or in a cycle analyst or in homebrew hardware, in a number of ways, yet still have a multi-KW system on there. Being unable to use more than whatever the limit is makes it the same as not having any more than that.
Of course, if you have something that allows overriding that as you ride, it'd be cheating, and if caught could cause you problems, depending on local laws and whatnot.
Around here, there are lots of cyclists, almost all on regular bikes, that create some of the problems all cyclists have with other people in traffic, attitude-wise. They don't obey traffic rules or lights or signs, ride on the wrong side of the road, weave around cars in slow traffic, ride fast on sidewalks ignoring pedestrians, etc. Wouldn't really be a problem except A) it pisses off the people that *do* obey the rules, both in cars, on bikes, and walking, and B) it causes accidents and gets people hurt and killed--not always the ones that are in the wrong, either.
On various bicycles, both assisted and not, I've been hit from behind by cyclists that expected me to run a light or a stop sign, both back before I started using markers, brake lights, and turn signals, and after, because the cyclists aren't paying attention to traffic any more than much of traffic is paying attention to them. I've also nearly run over cyclists that just go right thru intersections when it's not their right of way, or just hopped off the sidewalk in front of me, etc.
It's not something that happens every day (to me), but often enough it more than irks me.

And I see them do it all over the place, just like drivers in cars and trucks and motorcycles--they all do stupid things that break the rules/laws/common sense/courtesy/etc. Some of those things are harmless 99.99% of the time, but that one other time it gets someone hurt or killed. And probably wouldn't have happened if the rules had been being followed by all involved.
All of the accidents or near-accidents I've ever been involved in have been caused by others breaking those rules, and me being unable to predict that, and get out of the way or stop. Some of those rule-breakings were as simple as a truck stopping in a no-stopping-anytime zone to let their kids out to go play. There was traffic all around, and me almost ending up underneath the truck that stopped because of being unable to stop in time nor having anywhere I could go around. Not 10 feet further down is a driveway to go into the parking lot of the place she let the kids out to go into, and she could have easily turned and gone in then.
What is infuriatingly stupid is that after she let them out then she DID go into that driveway, to go park. She could have been hit by another car, as the kids were getting out, killing the kids if not her, if I hadn't been the vehicle behind her. Apparently she didn't care enough about those kids to think about that.
