Thanks for going through it. So I buy 3 Radeon RX 470s i should be making 91.90$ a month not including pool fees? But then why have I heard so many people saying mining is no longer profitable when with less than 1000$ of equipment you can make over 90$ a month?
Because negativity.
Also, you can get your RX 470's to hash at a higher 27-28 per card, and reduce wattage from 150 to 120W per card with tweaks. You have the basics right, figure out the more complicated stuff, and mining is pretty profitable.