Hmmm,
I put mine in a pump sprayer, straight (not diluted). I get maybe 4-5 36" plants with one fill ~2-3 gallons. I do a heavy foliar feed and a soil drench.
I would only cut it with water if I had to make it go really far, like for a lawn. Its all a personal preference thing, but I like it nice and rich.
Same here. I brew 5 gal and use it straight as a drench and foliar all at once.