Update. I bled the brakes using the helper method earlier today. There were very few minuscule bubbles to be seen (the size of a single dot made by a mechanical pencil on a piece of paper - yeah, that small). HOWEVER, the pedal did come up after I bled all four corners. It is better than the old master cylinder. I drove it around my quiet neighbourhood and activated the ABS via heavy braking. I also did so on my lawn. It seems to be fine for now but I will do another bleed (via helper method after I get the ABS to kick in) later in the week when I have time. That is, until my diagnostic cable and software arrives so I can do it the way the German's wanted.
Total Damage - one motive power bleeder, 3 cans of ATE brake fluid, one litre of Ferodo DOT4 brake fluid. ( Saving my last can of ATE for when the software arrives)
Considering - Stainless steel brake lines and genuine BMW pads in the future.