Those rages concern me. What does he do when he is in a rage? The rigidity that you describe sounds like it could be OCPD. Has he been officially diagnosed with that?

Pinksoil is right about the difference between OCD and OCPD. OCPD has to do with rigidity and inflexibility. It probably is hard on him adjusting to someone moving into his space too, although OCPD tends to bother the people who interact with the person who has it, and not really bother the person who has OCPD. They like to have things their own way. Your fiance sounds pretty extreme, though, and I wonder if there could be more to it. Maybe you could tell us more about why you want to be with him. The rages just are ringing a warning bell for me. Do you feel safe with him?