I'm not sure about angular misalignment, but the radial could be taken care of with an Oldham coupling - Google them, but basically it's a disc with two keys at 90 degrees to the shaft axis on the faces (and at 90 degrees to each other), and a collar on each shaft with a matching key slot, I'd guess if you're short on length the centres of the keys could be cut away and the collars could be quite short? They're popular for coupling steppers to leadscrews etc. in CNC conversions where there's slight offset to one of the shafts, might suit your application?
Dave H. (the other one)