Something I used to say to people back in the day of AD&D and RM1... that no, RM doesn't cover everything, and it doesn't try to. The beauty of it is not just in how it covers what it does, but that instead of grey areas it has places that are clearly marked, "this decision is left to the individual GM."
In fairness, that was RM1, back in the early 80s... I don't expect any revision that still has the feel of an ICE product to have such "crisp edges" if you will, ever again. Nonetheless, it seems like a good standard to strive for, even knowing in advance you'll never achieve it.