Neem is a no no for me while in flower.
I suspect yes, check the ingredients, if it’s pure Hypochlorous then your prob fine to use it. It is also sold as a cleaner / disinfectant. It is similar to bleach and can actually convert to bleach w a rise in ph so I don’t suggest mixing w anything but distilled water.
Check out this link for more info
Again, I don’t use neem in flower, but the isopropyl and Castile soap can help w PM but is not great alone at wiping it out. The hypochlorous is more effective. I use both alternating for my outdoor plants while in flower.
Good air flow, fans plus pruning interior of plant, and moderate 50ish rH is desired. Spray in morning before light is too intense.
You gotta make the call on when it’s time to chop, I prob would if it were me w these constraints. And no those buds look to young to be of much value to me.