Today I was accelerating hard on the highway in 4th, but still nowhere near the redline and I started getting the clutch pedal vibration again as well as a rough clutch pedal feeling, felt like it would if the mechanics of the clutch pedal weren't lubed up enough. I am really starting to think there may be a more serious problem here. Within a couple of minutes the vibration in the pedal and the rough feeling went away and felt normal again. I am afraid something isn't doing it's job right.
I will closely monitor the feeling as it comes and goes and address it with Subaru if I feel it again.