1) There are three combo attacks with exactly the same Golden Rune effect.
2) Base combo strikes (unruned) all generate exactly the same amount of spirit per hit (and per successive strike)
Another thing that will take the spotlight away from the Monk's otherwise interesting line-up of six combo strikes is itemization towards spirit generation. One could imagine stacking spirit regen and Attack on gear, and keeping just one or two spirit generator skills (not necessarily combos) for backup. Then the name of the game will just be spamming finishers. This is not to say that spirit regen itemization is a bad thing, but rather that even for combos, it's not difficult to imagine boiling down to an arbitrary one-size-fits all situation.