You can try bleeding before you replace the clutch, it can't hurt. I just replaced the clutch and master in mine because of the symptoms you are describing, but it still had a similar issue after the fact. The clutch was worn down, but not quite all the way to the rivets. Turns out, the bleeder screw itself was bad and even though it was tightened it wasn't offering enough of a seal, probably letting a little air in. Replaced the bleeder, rebled the system, and all is well.