[papajam]

Sounds all the world to me that the booster is no good; the result of brakefluid contamination. Not sure on the pedal return spring and cup. Is there another place in the pushrod closer to the booster where the cup could fit? Does the brake pedal move freely if the pushrod is disconnected?
The first thing I'd do for the clutch is to bleed it. Ensure that the bleed screw on the slave cylinder is at the 12 o'clock position or you'll never get all the air out. Next, I'd look at the clutch pedal pivot arm. Have a helper push down on the clutch pedal while you look at the pivot arm that acuates the clutch master cylinder pushrod. If the weld on the arm has broken and the serrations are worn, the arm can slip on the pivot shaft and not fully release the clutch. I'd change the master, slave and hose if there's no air in the system and the pivot arm is OK.