So true. I use ways that are said not to. But I made it work and know how to. Killed more plants then I want to say getting what I do down. I myself left for along time do to having to fight with people. What works for me might not work for you. But there might be something we know and have done...
Yes. Then get at least one water only between the next one and then you can go up then to. But your 5 weeks in so wouldn't try to force more then 1400 ppm on them. But your next grow should be killer.
Spray now. You have about 20 days right? So you would be fine. Also PM wash works good after you pull them if needed. Cut and trim. Let sit in the wash for a min then hang to dry.
If you have to yes. If they don't have the pm I wouldn't. But yes safer is OK on the buds. Just don't get then super wet. You can make mold or bud rot.
I can see the total from here. But like HR said some are to weak to flower. I have a similar setup for preveg. And over watering is really easy. So if I can say. Back off watering 1 interval. Best of luck