Get the Ver.2 44mm Steel driveshafts for the front of the car and you shouldn't have any more problems.
Put a bit of thread lock onto the diff screw and nut and this should stop it loosening. All the diffs have play in the pulley, this is normal and doesn't affect the performance.
Couldn't tell you off hand which way to turn the bearing holders, just turn them one way and see what happens, if it makes the belt looser turn it the other way
