Damn, alright, time to sift through all these replies. I'll be sorting them by the section they refer to.
I might just rewrite this entirely to better reflect the current meta, though honestly I do like the current tone and style of it. In any case I will be using the old one as a guide, since it does mention a lot of important things.
I'm not jumping to move parashuffler to OO because it is quite frankly VERY good at what it does (or at least it was in the past). I've had enough trouble facing it in the past... it's very easy to get pretty much your entire team paralyzed by it. I did use it once but that was on a really shitty team so I don't think my results there should really count. I think it should be at least tested in the current meta before we make any rash judgements. I will say that it probably has a harder time than ever before with all the new threats running around with Ice attacks. As for Pocket's suggestion of ditching thunderwave for flamethrower, well I'll give both a test and see what works better. I suspect that we'll have to keep Thunderwave as a slash at least no matter what, since this thing provides paralysis support like nothing else.
Bulky DD set:
Yeah I think that's one set I actually could easily integrate into the AC of the offensive Dnite set (though we'd have to rename the set obviously). It's not much different aside from running HP EVs, so I should be able to just slip that in along with a mention of an item that doesn't break multiscale.
Yes I agree with maxing the speed on it, makes the most sense. It allows it to outspeed modest heatran, most Cloyster and the occasional Togekiss at the cost of bulk you won't even notice. A good trade imo.
Mixed attacker Rain, Rain Tank:
I'm still a bit iffy on the EVs on the rain tank set, but other than that I like the suggestions you've given. The new spread and set you're putting forward also fits with the conclusion I came to when rewriting the classic Mixnite set; Extremespeed + Max attack is only for when you really need priority and mixed capabilities together. 176 outspeeds adamant Breloom (you're not outspeeding Jolly without going +spe yourself) which is probably a good benchmark to hit. Aqua tail / Superpower is good in the final slot, but Superpower should still stay slashed primarily due to the fact it doesn't miss at inopportune times. Aqua tail is definitely better in most circumstances though I think. And ExtremeSpeed will still get a mention somewhere of course, but probably not as a slash.
Ok, so are we in agreement this thing needs some testing? I mean it's such an odd duck that it's hard to tell if it's just a bunch of random stuff thrown together or actually a coherent and viable set. While my first instinct is to ditch it I honestly just don't know enough about it to make that call without some testing first.
Yeah after thinking on it I think Ice Punch is AC material at best. However remember that Waterfall doesn't provide the same coverage outside of rain and not every team that runs choice band Dragonite is going to want to / be able to run rain. I'd think where it'd probably go would be over EQ, since with Fire Punch and Outrage EQ is largely redundant, with Outrage or Fire Punch securing the same 2HKOs in most instances. While Gliscor isn't as common as it used to be it IS still common and a pain for Dragonite to get through. Really only bulky Heatran is what you'll miss out on a 2HKO on, and that becomes a 2HKO with just a bit of prior damage. It also gives you a way to KO opposing dragons without locking yourself into outrage, which can be pretty important. So while it IS situational, I still think it's AC material, not OO material.
In other news, I've done a couple quick calcs and found that Genesect is a 100% counter to Sub+Dance Dragonite, unsurprisingly. It might not be overly bulky, but resisting dragon claw and hitting with an Ice Beam backed by 120 SpA means Dragonite can pretty much kiss its ass goodbye.
Oh, and I'll add Scarf Kyurem as a check. I didn't even think about it when making the OP, since I was focusing on new threats, assuming the old ones to all be covered. Looks like that despite Dragonite's massive counter and checks section they still managed to miss one.
I'm going to edit the OP with what conclusions we've come to so far now. Time to get testing some stuff I think.