hmm, problem #2 is a real deal breaker.
the thing that makes a good cantilever brake is how you can adjust the straddle cable length.
To work around that, I'm quite sure you can setup threadless stud types so that the pads sit in closer. There's no rule that says the studs have to be close into the brakes.
Now that I'm looking at it: the brake shoes are set at probably the worst position. This is hard to explain, but the posts on the brake shoe are as far away from the wheel as possible.
I think I need to true my wheels so they are 100% even; they aren't now, and that's why I left a little room for the wheel to wobble. They aren't ridiculously out of true, but they wobble just enough.
I'll make it my mission to true the wheels and adjust the brakes tomorrow (if I have an allen wrench) and relay how it goes.