Not only a multirotor but a mutilater too.....

This thing is less crasy as the thing you was showing some times ago with an "airtaxi" in Dubay. On this craft, the props where also "legchoppers" mounted low. No negative comment about the danger of the props there from your side then. I do not understand anyway why so many designs have to props there. When the props are mounted above the structure, The crafts would be more easy to make autostable, because of a lower meta centric. But it is an interesting development in these crafts and you right something like this but more practical will be coming.

Being a pilot of one of these things helps if you can suspend your belief in gravity or have zero imagination....

will the legs be sliced off if he falls?

The people who drive cars on "frozen" rivers in the spring, the ATV drivers who don't use a helmet, the people who don't use seat belts and the operator of this medeval inquisition contraption all share something in comon and the older I get the more I can appreciate them. We like to call them "DONORS" Just keep them comimg - I might soon need a liver or a kidney.

Scary to be right in the middle of 4 rapidly moving blades. No way I would ride this thing.

Has no one yet thought to use ducted fans on these things, rather than open propellers? Seems like amputation would be much less of a hazard, with the added benefit that a ducted fan is more efficient. Carbon fiber could make the ducts very light weight, and the props could also be carbon, since they'd be protected from hitting objects or terrain and shattering.

how many horsepowers or kilowatts does it take, just to hover?

Boy, just LOOKING at that thing before he even fired it up gave me a severe case of the heebie jeebies on top of the willies! Oh clutch the family jewels! Truly cringe worthy for sure! Like they couldn't come up with some semi-circle shields made out of metal or carbon fiber to mount between the legs and the blades? Why were they not thinking here? Or maybe place a band around the blade tips and use 4 blades instead of only 2? That would increase the blade area by 100% with very little added weight penalty.

For almost 100 years there has been a debate about the difference in high wing (Cessna 152,172) low wing (Piper Cheorkee, Beech Bonanza) stability. This contraption has such a high "roll center" as to be almost ridiculous. Get it leaned over just a tiny bit too much it is going to keep right on rolling. Of course I am leaving out that it might have computer controls to keep that lean angle from happening but my desk top has crashed too many times for me to trust that idea on something like this. Then the one idiot gets on the thing w/o helmet. Donors indeed!