This is turning into more of a blog than a forum, but whatever.
Decided the nipple was likely Sch 80, possibly CPVC, not marked, so who knows. I couldn't get it to unthread from the other side, but there really wasn't a reason to anyway. I used the all purpose glue that's good for CPVC, Sch 40, and Sch 80 (and ABS for good measure), so it shouldn't matter what it was.
Got the horizontal intake all glued up and the pump in place, but the front of the pump is sitting a touch off the paver, so I need more sand under the front of the paver to get the right angle. Decided I'm not going to bolt it, at least not now. Seems like most people don't bolt them except in CA where it's code apparently.
I did go ahead and remove and temporarily cap (just sitting on it, since I need to blow it out still each closing) my pressure side cleaner. It was in the way of my new plumbing, and it isn't used anyway. I was considering maybe turning it into a return someday? It outlets between my skimmers though on the same wall, so might not be good for skimming flow.
I also forgot to get 2" sleeves, so I couldn't make my final joints on the output side last night. Going to do that first thing when I get home so hopefully it'll have 2 hours while having dinner and stuff and then can finish the wiring and pressure test/run it after the kids go down. Wasn't paying attention to the 240V fact when I bought my wire, so I have black, white, green. I'll have to electrical tape the end of the white to meet code, since it should be red.
This winter I might redo my intake piping above ground to be all 2" since it's 2x1.5" skimmers to the pad right now. Dig down, put a 1.5 to 2" adapter underground, then 2" through all the elbows, new 2" neverlube valves, and then 2" into the intake of the pump.
Main drain side would still be 1.5" all the way to the pool, and the return is still 1.5", but it's a start at least.