Posting again.
I pretty much agree all-round with the allowed/disallowed lists thus far. As far as controversial moves go, I would say that so far I have mainly seen support for Power Whip, and it does not seem controversial in that sense - indeed, it is far less so than several other moves that have been allowed or disallowed thus far. I will avoid restating the arguments already presented in this thread, and my position on the move has not changed since my last post. Of course, as I said in that post, the main issue with Power Whip is not that it is overpowered, but rather to what extent we want to make physical variants of Necturna a threat. So maybe it is better for it to go to the vote. We'll see.
I am still against all other moves under the controversial list, though my reasoning here may be somewhat difficult to explain - certainly, it was so on IRC. In this case, I would say that they should be disallowed because there is no positive effect that they can bring by being added to the movepool, and more than that, the only possible effect they can have is negative. If I may explain further - the only possible use for an Electric-type move on Necturna's moveset is to hit Skarmory (purely in terms of OU threats), and likewise, that for a physical Ice-type move such as Ice Fang, with regard to its being used over Stone Edge, is its ability to hit Hydreigon, Salamence, and Dragonite, three Pokemon we made it clear should check Necturna to a reasonable extent. The latter two are hit hard by Stone Edge and Hydreigon is mashed by STAB Grass-type moves regardless; however, this is not the point. The only conceivable use here is against Pokemon we have outlined as answers to Necturna - or, to put it another way, against Pokemon that by rights, one should be forced to Sketch moves in order to bypass.
This is not a good idea. Put simply, by placing a move that could conceivably be used against good checks, but nothing else, we are diminishing the value of Sketch, albeit not in any significant sense, and bloating a movepool. The actual competitive use of these moves does not matter in this case, since the argument is not about the relative power of said moves. Were Ice Punch actually used or not, it is still removing one other Sketch possibility from the table - and the presence of any Ice-type offensive move lowers one's willingness to actually use another move of that type - if you can get away with a weaker but functionally equivalent version while retaining Sketch, why bother?
Next we consider whatever positive aspects can be gleaned from a move being allowed. On any typical movepool, this is no difficulty at all. We can see what coverage moves we already have - there is no problem with essentially limitless coverage. There are no positive aspects to allowing Ice Shard and the rest. My essential argument is that they are inherently distracting, detract from what we are trying to accomplish, and limit what we can achieve - that's more or less the shape of it. Whether or not they offer Necturna any huge benefit in terms of movepool is neither here nor there. Of course, you may well disagree. Certainly do not suppose I have spoken of them as broken, for I certainly do not believe that. Any more than I think Bubble would be overpowered.
As for the rest? I still hold my word on Air Slash and Flash Cannon. As I have said above, it is not about their relative power on usefulness - they are still distracting moves. I am, thus, being quite firm on this point. Of course, if we are allowing Psychic-type moves, certainly the above two pose no risk of being overpowered, as such. In the same way, I would advocate against Meteor Mash, Acrobatics, and Drill Peck.
As for the final three, I have no real qualms about Fake Out and Super Fang, although especially for the latter, I would have thought that this would be a move that could easily be Sketched to suit the user's purposes, and as such is not so fantastic a choice. I am aware, however, that support sets, which stand to gain the most from both of these moves (well, maybe not Fake Out, but you know what I mean) will perhaps want to be Sketching some more potent moves, and as such Sketching Super Fang may fall a little by the wayside. I can't see it being used over Night Shade, but hey, support sets need more love. As for Extremespeed, I would reject it on the grounds that I do not want Necturna carrying around any priority stronger than Shadow Sneak, and that we all know what Dragonite is capable of with this move. I'd rather not just haphazardly slap priority on Necturna, especially when it has a perfectly good move of that nature already.
In summary:
Power Whip - ALLOW
Ice Fang / Ice Shard / Ice Punch - DISALLOW
Thunder Fang / ThunderPunch - DISALLOW
Acrobatics / Air Slash / Drill Peck - DISALLOW
Fake Out - NEUTRAL
Super Fang - NEUTRAL
ExtremeSpeed - DISALLOW
Flash Cannon / Meteor Mash - DISALLOW