You cannot test too much. It just uses up your chems and your time.

You are EXACTLY right that we learn our pools and KNOW how they react to things without as much testing.

pH and Chlorine are good daily tests. But unless you see something funky happening, I think twice a day is a waste--just do it in the evening is best.

Alk, CYA, CH--These are weekly tests unless you are actively adjusting them substantially. Otherwise it's just a waste of reagents because even if they change noticeably, you don't have to react instantly.

Again, CH in a vinyl pool without a heater or SWG is a 2-3x/season test.