After replacing the brake lines in the Bonnie the system was almost completely drained. My question is does the MC need to be bled before the lines or will simply bleeding the lines a sufficient number of times work?

The reason for the question is once the repairs were made, the lines were bled. Twice. Each wheel received 3 press 'n hold cycles before moving on to the next. The brake pedal dosen't feel right and the ABS begins to pulse with very little pressure applied.

Also, do these "speed bleeders" or "one man bleeder" valves work well?

I know we had issues with my system when I had lines changed. We tried to bleed it a few times and it still dindn't feel quite right. if you actually have the system chanrged up ( key on) it seemed to add alot of pressure to it and "shot" the air out of the lines. As for you MC being empty. If your system was charged up and you looked at it, it will be lower. On the MC it tells you once the car is off to pump the pedal 25 times, yes 25 times, then check the level again. It took a while but we finally got it bled.

I know that my ABS woudl kick in any time I woudl put the brakes on once I got to drive the car, but in my case it was the ABS sensor on the front drive shaft that was cracked.

No pump and hold cycle. Old wanna be mechanics lore. (housewifes tale)

Get 3'-4' piece of clear 3/16'* or 1/4" fuel line. Take bleeder with you or have them try on a wheel cylinger at the store. Or measure bleeder at home. I'm just not sure what size mine is I've had it for years. You want it to fit tight on bleeder.

Start at rear wheels. put box end of wrench on bleeder.
Put hose over bleeder , glass or clear jar at other end. Once you get fluid in jar keep line submerced
Get wife or girlfriend and explain benefits to lots of pumping.
Make sure master is full and caped
Open valve and let the pumping begin
You will see the air come through the line and work its way down hose into jar.
Keep pumping until no air.
No more than 10-15 pumps before closing valve and checking/topping master you can figure that out as you go
have pedal held down while closing valve
Just let the hose and jar sit
Keep pumping until no air.
Move to next rear wheel cyl and begin again.
same deal
move to front passenger side
same deal
move to front drivers side
same deal
start all over again at first rear wheel and see if any more air shows up.
go all the way around again
If satisfied that you have no air, check pedal
If you still have problem call doctor
Never reuse brake fluid.
This is a good flush out method too.

If you have anti lock breaks
call doctor