Should I pop off the lower bud sites or too late f...

Had this same issue when I grew my Northern Lights Auto ... Learned from a experienced grower that it's most likely genetics ... But as I've been growing I've seen some autos go for 144 days.

I would pinch them off. Your week 4-5 now ? You can do this. It will give you fatter colas. More dense. It increases the yield to’ Goodluck

Yes you can remove any lower budsites that aren't getting any light. The sooner you pick them off the sooner the plant will focus that energy on the top buds but you can remove them at any time during the grow and it won't hurt the plant. Good luck finishing flower.

Depending on the light penetration into your canopy, most times, a lollipop as it's called, is done around this time in a grow, you can see which buds will develop into decent density and which won't, indica's usually run around a 10-12 inch depth from the average top height at the time of the lollipop measured down. Sativas are usually more tolerant of a shallower canopy due to the stretching nature in flower, hybrids are somewhere in the middle.. after you've raised the canopy, feed and give them a rest period of no pruning or deleafing to recover from the lollipop, and several days later, I personally deleaf anything without trichomes on them, and in 23 to 34 through flowering, I remove any leaves that I can see stems or petiole on. Many people will probably chirp at me for that last suggestion, but trust me, once the buds have more leaf surface than the fans, there's no need to keep them, except for the top 4" of the branchtop where no leaves are touched except dead or diseased... Hope this helps, keep it Green! Cheers

You want about 4 to 5 bud sites on each cola to maximise the yield. Any more than that just prune of the lowest ones.