Can some genious tell if it works / doesnot work?
I don't think mass of magnet alone is sufficient enough to create centrifugal force which can hold the arm straight against reactive force exerted by the generator because centrifugal force acts radially, not tangentially. So, you may have to fix additional solid mass on magnet to get sufficient centrifugal force so that the arm can remain straight against tangential reactive force of generator.
Will not adding extra mass on the arm affect the performance of motor?
Centrifugal force depends on three factors, mass, speed and radius as in equation F = mώ2r. You can increase any one of these factors to get stronger centrifugal force. These factors have to be designed correctly while building the machine.
For any machine to work you have to consider two things :
1) Working principle
2) Design aspects
The working principle here is getting greater torque from a lengthy arm by rotating it with smaller arm with same speed without loosing mechanical advantage.
Various aspects like link, mass, speed, radius of arm etc., are design aspects which you have to consider while building the machine.
Just by reading Bernouli's theorem can you build an aircraft? While building an aircraft you have to consider several important design aspects such as angle of attack, shape of wing, length of wing, etc., if not your aircraft will not create lift.