Mazar (first time topping)

I have around the same wattage lighting as you and I have never had any issues with leaves burning from it. Does kind of look like a deficiency starting, I almost wanna say it needs more nitrogen but don't take my word. You should PH your runoff and start with a flush, that's the best way to correct most problems. As for late flowering... I mean who cares! XD The bigger the plant the bigger the yield :) No clue why it's taking so long ;p. I don't think you over fertilized but you could of, a flush will correct it.

Some autos just don't express auto genetics. Especially if the genetics haven't been super stabilized. I've experienced this and waited for the other autos to finish flowering and then flipped to 12/12 to get it to flower. By that time the plant was a monster and I managed to get 14oz of good good and another like 6oz of larf. So if you want her to start flowering now flip to 12/12 and you'll be all set. It is unfortunate that it can happen that way, but at least it is not a total loss! Good luck with the grow!