great write up. here is an idea that uses same positive pressure-closed system idea.
What I've used in the past is a medical syringe. Use at least 20cc one or you won't have enough fluid to charge system. get short tube (4-6") that will seal onto bleed screw and tip of whatever type syringe you use (there are two common types-lock type and cone type). Good seals are key here.
With everything hooked up and syringe almost full, pointing down (air will rise to other end of syringe), just push syringe down. it will push the air from syringe tube through caliper, brake line and all through the whole system and out the master cylinder, filling it also. again make sure you have the master cyliner cap off and not super full, and don't go pushing all crazy, its a low pressure system. when no more air bubbles, just fluid is comiing out of master cylinder, you are fully charged with no air in line. now tighten bleed screen before removing syringe-tube setup. works great. try it. syringes can be bought at most pharmacy, med supply stores.
sorry kinda long and wordy, but basically making closed system that starts with syringe, that you can press through system. takes some tinkering but hasn't missed a beat with me over the yrs.
no pics, but can add some later.