1. How do you switch the booms off and on, is there a switch that you flip? Or one on each boom that you have to "twist" like on the PG? 2. Can the hopper and sprayer both be controlled with the same switch? Or is there a switch / lever for each one? 3. At any one time, can you actually operate the machine with 400 lbs of fertilizer on it? 200 in hopper, 100 in each tray? 4. Where is the fuel fill? 5. How well can you spray flowables? Or iron / micronutrient materials? Is it a machine that you're basically using to control weeds spot spraying, and spreading dry fertilizer?