Scares me to read threads like this.
I'm still on a non ebike and have been in a couple of close accidents with pedestrians and other bikers... makes me wonder if on an ebike it may be harder to maintain control.
An ebike isn't 'harder to maintain control', but most ride them faster than a pedal bike, and you need to be aware of that when riding a path and sharing with other bikes and peds. Leave plenty of room in case they side step or dart, use a bell or call out, slow or stop when necessary.
We've done group rides with 8 riders up the busiest path in the country - the Hungtington Beach strand. It's not a problem, you just have to pay attention.
Offroad is a completely different animal. Until finer skills develop there is more danger in falling off, sliding out, tipping over. I don't worry so much on pavement, I haven't crashed a bike since I was a kid, but offroad has way more obstacles and challenges.
It's nothing like an adventure bike at 100mph +, or splitting traffic with thousands of cars. The latter used to make me sweat, but you get used to it - split tens of thousands of cars. The guys that don't are the ones that tend to get creamed, and it's generally an inattentive driver texting on their phone. Women in mini-vans and SUV's are something to watch closely for - notoriously all over the road, clearly not paying attention to their deadly machine.
We never really wore helmets on bicycles since the kids grew up, but with the new ebikes I got nice comfortable ones, and we wear them if were doing a trek. Going around the block i don't bother, but if we're putting some miles on then definitely, and close-toed shoes. NO FLIP FLOPS!! Just a fall off the seat - the 4' drop to the ground, if you hit your head, can cause a major injury. It's just cheap insurance, painless protection from a head injury.
I want to slap people up the side of their head when I see them leave their toddler unattended in a shopping cart. A drop to the floor can kill them. It's majorly irresponsible, the poor kid just doesn't know better, but you'd expect the parent to.
You can't live your life in fear, at least that's no way to live, but a dose of healthy caution and acute awareness can make all the difference.