Just a couple of thoughts:
I really like Cretacerus' idea for Whirlpool. If Mollux is supposed to shut down rain, why not trap and poison away? I really like this.
I'm also in favour of allowing Recover for pretty much the same reason as Bugmaniac. I think Mollux should have greater healing capabilities and any other healing move ie Morning Sun, Moonlight etc doesn't seem viable due to the unstable weather in the metagame.
Disallow +2 Speed moves. I can quickly see Mollux being drastically overpowered and broken if it managed to get some speed on with that high SpA stat and coverage.