I posted in this thread before and just came across it again so I'll post a follow-up.
I'm up to almost ~120k miles on my 08 WRX now.
I had the clutch "clicking" sound for the longest time when releasing the clutch pedal. I found it to be associated with the clutch linkage as stated above. It went away eventually. The odd time it came back, I found that kicking the clutch pedal laterally in the direction of the brake and gas pedal made the problem go away. Now that I see it could be popped welds, I'll look into fixing it myself.
I also had the vibrating clutch pedal problem intermittently but it hasn't happened in the last 6 months. When it did happen, I only felt it at the top 1 inch of travel.
My clutch has always been stiff unlike many of the newer subies I drove. I have not replaced any clutch-related components on the car (mostly because I went through the warranty period in under 2 years). I found it more annoying than anything and I'm glad the problem went away.