My experience may be a bit biased though, considering I'm both a pretty experienced cyclist and I have to deal with the crazy San Francisco hills.
EDIT: Also, I do a fairly regular 12 mile round trip bike commute. Have only done it a couple times on the scooter for fun and it was terrifying compared to my bike.
Higher rake means the bike pitches in response to the wheel turning, because the contact patch is less in line with the handlebars. Wide tires multiply that even more. That gives stability at high speed but when you try to turn the whole vehicle moves the wrong way, making steering lag. It also makes it harder to stay up.
I'd actually say all forms of transportation are significantly more dangerous in the bay area, haha.
Kick bikes are incredibly unstable compared to bikes at their typical low operating speeds, and positively unusable at anything approaching biking speed.
And that is not even considering humidity. There are some days you can just open your front door and you are immediately sweating.
Not sure about the safety. The fall to the ground isn't what gets you as a vulnerable road user: it's the car.
I certainly don't, although I also readily admit that any option that leaves me exposed to the elements would be a major step down for vast portions of the year. But for many days an e-moped might be a reasonable option.