Hi, welcome.
I am a novice becoming a master, lol. I had all these same questions. I started out using my cabbing 8″ flat laps. Used the ultra’s and finally ended up using Lightning Laps from Kingsly North a US company. By the way guys there stuff is better and affordable, you get what you pay for. I use 100 topper to remove material fast, but it has to be large, ( time saver ), 220 topper I use to rough in to 2 mm of the size I want or am to get. From there right to my fine 1200 lap ( meets) from kingsly and I will be getting that 3000 when available. LL makes a cerium topper for $30, well worth it. I use all their laps up to and I have 200k, I am not there yet, but ready, still learning on quartz and cz. How in the heck does one polish corundum?
Lot of good advice here.
Thanks to everyone for being here, I am so grateful.