Yes it is more dangerous, for the simple fact that falling on your back and slamming the back of your head on concrete is a very real and considerable danger, and its effects can be extremely severe. Skating helmets are shaped differently from bike helmets because of this one thing. It's not a common occurrence (I see people falling forward and injuring their knee or hip ~100x as often), but can be deadly.
For casual, daily commuting I wouldn't say it's more dangerous on average. I've had plenty of minor accidents while I was learning (I'd say first 12 months), mostly scraps and bruises, once a twisted ankle. If I compare it to how I was learning to cycle as a kid, it's a very similar experience ;)
The hardest part will come from learning to manage your front/back balance in addition to left/right. It's always safer to keep your weight forward, it will also keep you more stable at higher speeds.
Overall the longboarding community is extremely serious and conscious wrt safety, unlike some street skateboarders nobody will ever point a finger at you for casually wearing a helmet and/or pads, and if you'd ever try anything remotely related to freeride/downhill/sliding without adequate protection, you're likely to have your board taken away until you suit up. I believe natural selection had something to do with that.
> I'm always amazed by how skaters are able to stop or "hit the breaks" where there are none.
Where you see no brakes, I've counted 5 different methods to control your speed, all of them have their uses ;) In the order you'd learn/need them: bail, footbrake, carve, slide, airbrake, bail (again). Simply stepping off the board is most effective at sidewalk speeds, all you need is reflex and balance; you'd also learn to fall. At 20+kmh, footbraking (dragging your foot on the ground) becomes necessary as bails can hurt. Down a mild hill, carving (slaloming) will help you keep your speed down, without touching the ground (and grinding down your sole, foot burns are a thing lol).
At 30+, you almost certainly are going to need a helmet, it's also when sliding starts being effective (never EVER slide without a helmet). Airbraking is simply the opposite of tucking - instead of curling down to make your body shape more aerodynamic, you stand up and spread your arms, it can be the difference between going 30 or 60 down a hill. Lastly, if you need to crash safely at 40+, you learn how to ride out your speed on your gloves, pads, leather, etc.
This is someone I know, he rides with his crew quite regularly and this video is from a hill in Greece near my hometown. https://www.instagram.com/p/CEzGpGnlzTh/
