1. yes, the rpcs3 dev made a change not a long ago to lightgun/mouse and its a mess ... what you need to do is this: after you make the ps move setting, in calibration screen you need to press CTrL+F11, then you can move and press the mouse to calibrate. after you ingame, you need to press CTRAL+F11 again to let the keyboard take control and move in the manu. once you start the game, push ctrl + f11 again to make it work with mouse/gun.
this all thing is just a mess, i prefer just use the old rpcs3 version that work well with the sinden instruction. look for a march 2023 version to download in rpcs3 site.
also you can just use the new guncon 3 setting, but i find the crossair slower for some reason than the ps move.
2. they also change the "Save.state" file to something else and i didnt find a way to save and load after calibration with this new save file format. maybe someone else will have a better luck.