A little rain won't hurt? Should I start with max yield and taste nutrients next week? I think they are in week 2 of flowering now?

if you are new, i'd suggest keeping things simple for a few grows.. just keep it healthy as you would any other plant. REact to symptoms in leaves, when necessary. Try the gimmicky products after you have a good baseline and determine if it has any effect you can recognize. "taste" nutrients sounds like a marketing thing :P People used to be adamant that adding sugar to the soil would make their buds sweeter too, despite the fact the sugar compounds couldn't physically enter the plant. Lots of myth sorrounds horticulture.. whether it's growing flowers or marijuana. People are desperate to grow 'special' plants.