Unfortunately there is zero enforcement. Either there would have to be a massive amount of police controlling how people drive, or they have to be banned.

I don't think I've ever seen the 45km/h version on bicycle paths though. The 25km/h versions have similar problems as described, so I'm guessing they were what was referred to, but they definitely don't go that fast.

Depends where you live I suppose. Some areas are perfectly fine. Mine unfortunately has a lot of social issues.

I have never seen a speed pedlec on a bike lane inside the city. I can't even remember the last time I saw one in the city generally speaking, as they don't seem to be extremely popular.

There used to be a way bigger problem with enforcing of scooters in the bike paths, though that is now way less of an issue, as far as I can tell. The only scooters legally allowed on bike lanes are the ones limited to 25kmph. I still find them dangerous, but considerably less so than how it was a few years back.