Seperate line and load conductors. Seperate signaling (control) circuits. Yes, individul conduits. Install a line reactor for each control (VFD). If motor is more than 100' away from drive install a load reactor. Inductive currents from the drive output will dirty up the input conductors causing nuisance tripping of the drive. The only place where the conductors should meet is in the control panel. Keeping control, line and load away from each other. You can use one breaker and a terminal block for several drives. But you should use seperate line reactors.
Note: Some VFD's have the reactor built in.
and look under brochures or manuals. You can get anything you want there in PDF format.
Or search Trans Coil Inc. for line and load reators and further information.