I'd avoid ANY systemic pesticide after week 1 of flower. Many pesticides are not safe for food crops, and I'd avoid those as well. You sometimes see growers using Floramite- I'd personally never touch the stuff.
Also, hormone products are something to avoid in flower, unless it is something MADE for cannabis. I've used Messenger (harpin protein, a turf booster) on vegging plants with good results, but again, I'd never touch the stuff in flower.
As for the orchid, violet, tomato-specifc ferts- they are just different ratios of the same compounds, and may not be great for the plants, but aren't hazardous to humans.
When in doubt, stick with chemicals approved for food crops.