RE: DougJustDoug
I support both Ice and Rock moves on this pokemon simultaneously for several reasons. In fact, there's even a precedent for them: Poliwrath. This strikes me as a kind of OU edition of Poliwrath.
Poliwrath, for the record, gets only Rock Slide and Ice Punch. In it's relevant metagame (UU), even with these moves it cannot solidly beat its grass and flying counters without using a Bulk Up or Belly Drum first. Meganium, Venusaur, and Vileplume can all stave it off. Altaria is pretty much the lone exception, and even it can try a Toxic + Roost strategy on bulkier versions.
It is my contention that Tangrowth and Celebi act as the OU counterparts of their UU versions. They can easily stave off the UnSTABBed attacks with mediocre BP and get a KO sooner. They have more trouble with a Bulk-Up type set, but not so much that they cease to be reliable switch-ins.
As far as Rock Slide, Poliwrath almost never uses it. This is because the primary Flying threats in UU are neutral to Fighting, and thus not particularly fond of coming into Poliwrath on a Substitute. Focus Punch does more damage to them than SE Rock Slide. It is the same with Electric Pokemon really, where SubPunch is a decent alternative to Earthquake.
I do submit that Stone Edge has the potential to be problematic on a Bulk Up set. In which case Gyarados' Intimidate becomes moot, and it will be unable to reasonably expect a KO. Stone Edge does of course have it's low accuracy and low PP qualities to dissuade it from use. I say it should be kept.
However, Ice Punch and Rock Slide co-existing on a Water/Fighting pokemon has already proven not to be unbalancing to the relevant tier. I don't imagine in a tier crawling with high-defense Fighting neutral Steels that the combination will cause any undue strife.
Of the Controversial and Pending moves, I lend my support (Allowed) behind:
Rock Slide and Stone Edge for reasons listed above.
I would also like to move Thunderpunch down from Allowed to Controversial. Unlike Ice Punch, which applies to an attack type most water pokemon get and most Grass and Flying types assume Water Pokemon may carry, Thunderpunch helps it defeat pokemon it would otherwise have no explicit advantage over, such as other Bulky Waters. Effectively it makes it a counter against itself.
Bulk Up (there is no reason to believe this will lack Bulk Up) + Thunderpunch removes any chance any Bulky Water could stand against it. Only Suicune, which could Roar it away, stands a chance against a CAP6 with a Bulk Up + Thunderpunch set.
Finally, I believe Sucker Punch should be moved to Unallowed. a Fighting/Dark kind of priority coverage has already proven potent with Revenankh, and Sucker Punch also plays extremely well on a Bulk Up set. Too well, in my opinion, because it eliminates faster offensive Psychic counters.