"And unless the lift fans can tilt even a little, forward air speed, and low-speed low-altitude control (you know, takeoff and landing, the most dangerous parts of any flight) will be even more interesting."
Making the fans movable just adds weight and complexity when all you actually need is for them to be individually controllable. Want to move forward, increase the rear fans with respect to the forward ones and tilt the whole aircraft If you look at the photo you'll notice that alternate fans spin in the opposite direction so by varying the speed of the CW fans vs. the CCW fans you can even control yaw at low speed.
"both the lift and the drive fans are not shrouded; that thing's not roadworthy"
It's a development vehicle FFS. The patent diagrams clearly show shrouded fans.
"the fuselage appears to have a very narrow cross-section. I do hope that the designers paid close attention to the internal bracing"
No, clearly they don't know what they are doing. Perhaps you should give them a call.
"speaking of structural integrity, what's it supposed to be made of? Batteries are heavy. "
Please direct me to the part that says it's battery powered.
"a headwind of even 10 knots will radically affect the effective groundspeed."
Yes. It will affect it by 10 knots and over an hour it will cover 10NM less, irrespective of whether we're talking about this aircraft or an A380.
"Depending on the maximum airspeed that thing can attain (which won't be much, not with those tiny pusher fans, not unless they're Really Fast Fans(tm)) ... how well does it glide, when (not if, when) the batteries die in mid-air? Not very well, I'm guessing, not with the drag from the fans (too small to even think about autorotating) and not with those pitiful main airfoils."
I would assume those "tiny" pusher fans are capable of generating enough forward movement to generate the required lift from those "pitiful" wings. Cake, eat? Once again, I'm sure they'd welcome your input.