Re: sproket wobble
You should be able to get that sucker pretty much dead on, with no wobble. I played with my sprocket mounting for what seemed like forever in order to get it lined up right, and it eventually paid off - I had no detectable wobble whatsoever.
If you can notice that wobble at slow revolution-speed, then it will be quite pronounced when your bike gets up to speed.
So keep messing with the sprocket mounting until you're convinced that the wobble is gone (assuming that your rear wheel is actually in true, and your sprocket is a good one). If you're still not happy with it after that, check out Manic Mechanic's link on the left-hand side of your screen - he makes a "sprocket adapter" that will entirely eliminate your wobble (I believe there's also another guy on this forum making them now too).