So confused about chemicals

Howdy from Texas yaw... I'm new this business. Long story short I purchased a high pressure rig to help a young man get into business. I'm fighting over a couple of things... exactly what chemicals do I need to stock and d i need to invest in a low pressure or a softwash system? Here is the list I have compiled as far as chemicals... Barc F9, F9 efflow, wd-25, EBC, Dragon Juice, 10-15% Sodium hypochlorite ( bleach ). Are there other chemicals that can be purchased that have oxalic acid for removing rust? What makes the Dragon Juice so expensive? What is the best soap? Do i need roof snot... seems like a lot of products, just trying to narrow down what I really need to cover most residential jobs. I want to do roofs once i figure all of this out.
Thank you
Keith Rowe
AmeriClean Pressure Washing
Houston, Texas