Are you using kools-stops that are 1 piece with the post? And when you say they move around do you mean rotate in the holders?

I find Mafac racers very hard to set up really well since the amount of torque you need to put on the pad nuts to prevent the above often screws up the adjustments. Are you sure you are doing up the nuts tightly enough?

For squeal, careful toe-in adjustment (using the factory authorized Big Cresent Wrench) works wonders....

I have Diacompe GS levers with my Mafacs with full hoods and they work fine....

Mark