Yes. That varies from collet/flywheel to collet/flywheel. Some collets are shorter and require shims to push the flywheel out far enough to line things up right. I've had to grind the back of a collet down so I could move the flywheel back far enough.
Yeah, just sounds like you have a bit of binding on one tire sending the force through the drivetrain instead of the diff to the other tire. That combined with low viscosity oil or grease will cause what your seeing. Might want to pull the wheels off and check the bearings to make sure they...
If it has the 17mm hubs, I believe they are all the same normal thread now. Depends if you have these flange nuts: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMDC0&P=ML
Or if you have normal flanged black on one side and silver on the other. I believe the silvers were reverse thread.