Hmmm . . . lever-clicking stuff may be related to an inherent problem with HFX 9s. Weak point in them is the actuator rod, or more precisely, the ball end that pushes the master cylinder plunger. If the bike's ever been crashed / dropped, the lever may have tried to rip the rod out of its seat. There is a washer behind the circlip that holds the ball end from popping out. See if the washer is deformed. That could be making the rod hang up as you try to squeeze it. The washer should be flat behind the circlip. If it's not, or if the hole is enlarged or ovalized, the washer needs to be replaced. Eventually, if the hole gets enlarged too much, the ball end pops out and the lever swings free with the rod still attached.

As far as the pads not retracting, hopefully a more expert Hayes person can enlighten us. I encountered it once with my Stroker Trails but it disappeared again on its own the same weekend so I never had to chase it down.