It is highly recommended that you replace the coupler whenever you pull it off the shaft, as it should be press fit on to the shaft, and once you pull it off it'll slip back on. I wrestled with spending the extra 120 bucks when I pulled mine but ultimately felt that it was needed. I bought a split coupler to replace the original, and in theory I should be able to put that one back on if I pull it. For sure your shaft should not align with the rudder, that way you can pull the shaft without pulling the rudder.
I pulled mine last year, and did as much as I could think of before putting it back in the boat. Replaced the strut bushings, checked the shaft for runout and penetrant checked it for cracks. Lap fit the prop (much easier to while it's out of the boat) and replaced the shaft log and packing.