Flipped. How’d I do with the underside?

To be honest, it looks like you have done enough already. After you are done with the stretching in the first few weeks into flower then re-asses the situation and go from there. You can check out my latest grow diary on my massive single plant 4’x4’ scrog. Your goal with a scrog net it to create an even canopy and if done correctly you will not have any light coming down below that canopy line. That is when you trim of anything under it but it takes a few weeks to establish that canopy. Your best bet is to tuck some branches under and make sure nearly every hole is filled up. This will even everything out and spread the plant out quite a bit. Remember, the goal is to create an even canopy. I hope this helps.

It depends how vigorously this plant will strech during first two weeks of flower. I ussually lolipop few nods less than you did and make my final arrangements after flowering strech is over ( day 16-20 ussually) Time will tell, to me it looks overboard a bit ;)

Hard to say from this perspective. Its never too much, if everything you cut away was unhealthy and/or shadowed by the canopy. But everything more than that is too much, i for example would never cut leaves that get light and look healthy, no matter which height. It simply energy you cut off that your plant could turn into buds. And i would take away the net, right now its not doing anything but promoting mold, i would always advise you to put the net under highpressure so its not capable of soaking in water that much and doesnt get wet. GL mate