I like the idea of a forum health bar, since it can help warn you how much danger you are in at a glance, but I do agree that the strikes should come of over time if you have no infractions, Think something along the lines of points coming off your driver's license (I think the rate is one every six months, but I could be wrong).
But then that raises the issue what if people are dicks and only behave long enough to get the strikes taken away before going back to being a dick again. There needs to be a way to monitor that, and as far as I can discern, that would not be easy (of course, as I'm not a mod, I'm just speculating).
In reality, though, I just try to keep my nose clean and my temper under control, and so far, it's worked.
*Shines Neo Badge*