A few thoughts, some of that I already shared with Obi One.
I have a bit of experience in longboarding (carving and sliding), and I own a few pairs of trucks and wheels. I tested every setup I could to get experience. Now I am testing different trucks with different bushings, trying wedging/dewedging on the front and the rear... I am trying to find a proper lean-to-turn ratio and bushing resistance at the front and the rear.
For now I found that Randal II 180 longboard trucks with flipped hangars and softest cone bushings (also flipped) work best. Zero wedging. I also tried Holeys with smokey bushings, but being 60deg trucks they turn much sharper with much less lean, which does not resemble skwal's tilting on the edge sensation.
For wheels I simply use Abec11 Grippins for no slip at all, BigZigs work well, too. I would imagine that any grippy wheel would be allright.
I created two skwheel boards, about 1m long, one with a little flex and the other with no flex. The one with flex works much better.
Haven't tried any bindings yet, just grip-tape, I worry that nailing your feet to the board may be dangerous on the tharmac in case of falling. I also noticed, that riding without bindings makes me extremely aware of the weight placement (feet clock!!!). So it may be actually beneficial for learning process - I already noticed a lot of improvement with push-pull/feet clock coordintation. But I can see clearly how much more control I would have it my feet were somehow fixed to the board. It would be insane!
Frankly, I think it is not necessary to worry about radical skwhweeling. I honestly believe it is not possible on the asphalt due to limitations of grip. It is not the edge digging into snow, these are just wheels that will slip if you apply excessive lateral force to them. I will be more than happy to be proven wrong, though!
Sliding gloves, elbow guards are a must, protective/sliding pants and knee guards are highly recommended. Of course the helmet is absolutely obligatory!
Here is first hour riding the prototype:
http://www.youtube.com/watch?v=mFKLCjMIeE8. You can see me trying to apply feet-clock, push-pull and even tilting. The fact that I am even able to try these is a proof of the idea working.
In summary:
1. I think the skwheel great technique and balance learning platform. Pushing it up the hill is a great exercise for your quads.
2.
At this stage, I doubt it is good enough as a standalone board. I mean, if someone does not ride skwal, he will not see any benefits of the skwheel over a skateboard, longboard, freebord, T-board, whatever-board.