The thing is, evap. rate, trub loss, kettle losses, and all the other fiddly bits are very system-dependent. For example, I can drain my boiler almost to the bottom. Other people leave behind 1/2 gallon or more.
Rather than track each of those individual losses in my system, I just formulate based on a 6 gallon batch, and plan on draining 5.5 to the fermenter. Any leftovers can go into the freezer for starters.
As for boil off rate, that depends on your system and environment. My system (keggle + jet burner) boils off around 1.5 gallons per hour, regardless of batch size. Again, I set my pre- and post-boil volumes by hand, as the percentage loss (as most programs calculate it) is strongly dependent on batch size.