Toxic Spikes is the perfect way to make Poison-type an important part of Mollux, supporting the team and making Venoshock viable. At first I thought Mollux would be fine with just Toxic Spikes, but Rising_Dusk completely changed my mind. Mollux would be outclassed by Tentacruel as a Toxic Spiker without them, so I think Stealth Rock, Rapid Spin and Toxic Spikes should be allowed.
Soak sounds like an awesome gimmick to me, I'd love to see it allowed.
I think Magnet Rise should be disallowed. It just works against Pokémons that are supposed to deal with Mollux.
Morning Sun/Moonlight would make Mollux more usable in Sun, and it shouldn't have more than Wish and Aqua Ring in rain. So I think Wish, Aqua Ring and Morning Sun/Moonlight should be allowed, but Recover should be disallowed.
Trick is a nice move to make Choice sets viable (specially with Eruption in the Sun) and I can't find a reason to disallow it, so I think it should be allowed.