Found some issues with my ongoing brake problems, more q's

So I've had a problem with:

Soft overall pedal feel
Pedal firms up after a quarter push
emergency stops fade/smoke.
modulation is poor (when pedal first pressed, a slight psshh is heard, is that normal?)

What my setup is:
Cobra brakes all 4 corners (38mm piston fronts)
stainless front lines
hawk hps all 4 corners, fresh
cryo-frozen / slotted rotors
ABS currently disabled, 2 rings have small dings causing bad readings. (disabled by pull of fuse)
stock gt master cylinder
new oem rear lines.

What I've done to troubleshoot:
System flushed and bled twice
checked caliper slides and pad/rotor wear (basic visual)

What I found was that the pin on one side of the car was frozen. I believe that's the source of some problems, especially the fade and smoking I saw on that side during two "emergency" stops (The traffic here on the large hwy's in Scottsdale have some unusual traffic patterns, usually caused by people not paying attention in front of me)

So, instead of fighting this setup anymore, I've decided to jump on the brembo bandwagon (even though it may be overkill for my uses, I decided that it was an excellent justification to go to all new parts). So I'll start with the included pads, and eventually move back to Hawks.

My first question is: for my current rotors, I know the swept path on the new brembos is different (larger) than the cobras. Should I turn these? Or look into a low cost replacement rotor to hold me over until I can afford a set of Todd's 2 pieces (to avoid what we've seen with the 1pc rotors on the brembo setups here). I know they can be turned, just have to cut lightly, my concern being the loss of mass causing a loss of performance. I wouldn't cut them if I was just installing new pads, but the rotor thickness is likely to be different in the formerly unswept areas.

Next question, the "pshhhh" sound when I initially press the pedal, is that normal? I've thought about replacing the master cylinder at the same time, I thought that might explain some of the issues I've had with the pedal feel. Any thoughts on this? i'm supposed to have a rock hard pedal setup with the 1995 GT master cylinder and the cobra pbrs'. Other cars with similar setups had a much better "feeling" system.
 
I had a 95 GT and I put Cobra front brakes on it. It sucked. I had a mushy pedal the first half, then it was a rock the second half and it would not stop for chit! Since then I have learned that others who put this swap on use the Cobra master cylinder. The boosters are the same between the V6, GT and Cobra. Try that next. As far as the "psssh" noise I don't ever remember hearing that while driving. I do remember hearing that when I pushed the brake while bleeding the brakes...(engine off, key on). Your booster could possibly be leaking but before you replace that I would try a Cobra master cylinder.