Barney's Farm Mimosa X Orange Punch Auto

This strain got a flowering period of 70 days so 10 weeks. They still need to flower for 7 more weeks till they are ready for harvest. I think that you misunderstood it and that you tought that the full grow would take 10 weeks. But the time given by the seed company is only the flowering time. And it will start counting from the moment that you see the first pistils (white hairs). Your plant just finished early flowering and still got to mid and late flowering. Download the feedchart from advanced nutrients and continue from mid flowering.

Looks like potassium deficiency, could be nitro toxicity too most likely potassium

You can cut them known as lollipopping before switching to flower, you could probably cut a few off now but if you'd like to keep it, yes adding extra lights to hit the side would definitely help. Certain lower bud sites will never have much potential though. You could also Defoliate some of the fan leaves covering up other bud sites. Dont over do this though as you're done producing leaves. Usually the leaves covering inward of the canopy gets cut, pointing outsides of the canapoy stays

Correct as far as I'm aware this Is completely normal.

Just invest in a filter 😅