Haven't been to the thread for a while.
-Yes, magnets are "like a glass of water". Once it is competelly full it can accept no more. The biggest problem is being able to accuratelly determine this (as axplained previously).
-Unfortunatelly, I think you can hurt (read-change into many smaller magnets
a magnet with a field too intense. Check out "Quarter Shrinking" online. It is absolutelly scary, and I would never recoment anyone do this because they take things to an extreme. I'm not sure, but it may be applicable to our magnet material as well.
-Timmay70. Couldn't really follow your post, but yes it is possible to change the motors timing by moving the magnetic field about. The probelm is that it is usually not the best option, because in many cases it is detrimental to the efficiency of the motor and will make them run hotter. The best options are rotating the endbell, and or using a timed brush.-Jeff