2) According to the FAQ, one should force shut the brake line with a clamp to bleed out the excess fluid. Before flushing?

I'm with you on the line clamping, although it is advocated by the pros. It just seems like asking for trouble.

As long as a bleed valve is open a full turn, and the piston pushed back slowly, I doubt there would be a reverse flow of crappy old fluid all the way upstream to the ABS modulator.
--
Bruce Young,
'93 940-NA (current)
'80 GLE V8 (Now gone)
'83 Turbo 245
'73 142 (98K)
'71 144 (track modified--and still here)
New 144 from '67 to '78
Used '62 122 from '63 to '67