Just to be sure:
If unit is slowed down equally or more than it's movement speed can it still turn on the spot, reform etc. ?
Yes.
Can you slow down a unit more than it's movement allowance ? So could a 3 speed TUG be slowed by 4 MU and stay immobile even if pushed trough fire or would the max be slowed down by 3 MU even if hit by fireweapons with 3 "S" results and so pushing trough even by 1 MU would still be possible ?
In short is there a limit to the slow down or is there no limit based on the max move of the target
Nothing in the rules says that a unit cannot be slowed down by more than it's movement allowance.
Richard
OK so that is now clear 8)