Overview
This is is fine. If youre going to mention weather if at all mention how obscure rain is as a playstyle, and a quick word about how Victini is cool on sun teams is enough. Also, mention how 100/100/100 bulk is pretty solid for an offensive poke.
Wall Breaker Set
Fine, however one of Victini's greatest counters is Heatran as it prevents Victini from doing any damage at all without ungodly predicting skills. Other counters like Tyranitar might not mind a CB, but they can get popped for good damage with U-turn or finished off when weakened with a safe V-create. Defensive Heatran definitely doesnt like CB. Good job that you didnt mention that sub LO set I came up with, because in reality it's just too inflexible and is purposed to beat too specific of a threat to Victini.
The first tip is questionable when team preview exists. It's not hard to distinguish when its a good idea to V-create or U-turn. If the opponent has something that prevents V-create from doing good damage, such as Heatran, Tyranitar, and excessively bulky resists like, say, Slowbro then it should be advisable to use a coverage move or U-turn, your opponent has little to gain from such an early game predicting and staying and potentially losing an important poke to V-create. If the opponent has only a decent answer to V-create such as Rotom, or Landorus-T blasting them with V-create is more beneficial than switch advantage as you do your Job wall breaking even if you dont get a kill. Always u-turning early doesnt seem like the right choice.
As for team options, mention some more hazards clearers. SKarmory and MEga Blastoise are mentioned. Skarm is fine, Mega Blast is kinda meh, not the first thing I'd choose. Latis have shit synergy with Victini they further exacerbate team weaknesses, Scizor is bretty cool, especially Mega, it can deal with some Pokemon that give victini trouble like Ttar. People dont use that set enough. Mandibuzz and Zapdos are also noteworthy to mention though neither much care for T-tar ~_~. Hp fighting Latios is very cool, it can Lure and snipe Ttar/Bisharp pretty well, and it defogs, though I think im getting ahead of myself here. Ninetales are is arse outside full sun teams, if youre going to mention it dont do it in the same sentence as Zard Y but rather something along the lines of "Victini is a very impressive wall breaker on dedicated Sun teams, alongside Ninetales and Dugtrio for support Victini makes short work of the defensive metagame". Also for Duggy mention it traps Zard X, Victini's greatest Counter.
Scarf Set
Im.. not sure how good this is now that Gene and Luke are Dead as Dreams. I think I'd like to see one for now though. It forces a 50/50 with pursuit Bisharp / Scizor / Aegis at -1 which means it isnt super vulnerable to pursuit, in my eyes thats acceptable. Tyranitar is a hgue problem ill admit, but you can predict with U-turn or take advantage of a ttar choice locked into Pursuit.
Name: V for reVenge Killer
move 1: V-Create
move 2: Bolt Strike / Trick
move 3: Final Gambit
move 4: U-Turn
ability: Victory Star
item: Choice Scarf
nature: Jolly
evs: 252 Atk / 4 Def / 252 Spe
V-create still hits pretty damn hard making it a cool revenge killer / scarf user, it can get a kill basically every time it comes in against offense, and easily pops fast but frail threats like Greninja (depending on its type), or Thundurus. FInal Gambit might seem dumb as a main slash but I promise it isnt. Victini cant revenge kill Dragonite, Charizard X, or Mega Tyranitar without it, and with it, it can. It sucks becuase you have to keep Victini totally healthy to do this, or damage the opponent on set up pretty bad, but if you can do this then Victini's revenge killing ability is on par with quite a few other scarfers in XY OU. Final Gambit is also cool against stall because Victini is very easy to wall for them, and you can pop something for a huge chunk and gain switch advantage. Common answers like Heatran and Quagsire for stall can be taken out of the equation by controlling momentum to prevent healing after Final Gambit has done its work. U-turn is necessary as a scarfer to pick off weakened stuff and not lose momentum! Readers must know when to use Final Gambit (against +1 mega ttar or full stall) and not to (when the opponent has something youre needed to revenge kill later like Scizor or Greninja) so detail this. The choice between Bolt Strike and Trick is a choice between matchup vs offense or defense. Tricking your scarf away is really only a good idea against full stall because the point of a scarfer is to bring speed to your team, however against stall it is quite beneficial and should be done as early in the game as possible for a number of reasons, one being that Zard X, a good stall mega is threatened by Bolt Strike early game, so an opponent is unlikely to switch this in while Quagsire or Hippowdon are more safe bets for stall so you can be successful. Trick can also be useful to stop bulky boosters like CM clefable or Crocune in their tracks as well it can totally ruin Bisharp's day if you give it a scarf as it sucker punches. Bolt Strike provides you with useful coverage and although its weak, offensive weaknesses to it like Keldeo, Base Greninja, Azumarill, or Charizard are obviously way easier to take on with this.
In team options, take a look at the relevant pokemon in XY OU that can take advantage of Scarf Victini, basically any Fire-resist and offer teammates to mitigate that. For example V-create locked Victini is total set up bait for Charizard X, Belly Jet Azu and a lot more. Ways to mitigate this are important.
All Out Special Attacker
This set looks fine, however mention Grass Knot somewhere in moves to snipe Quagsire/Gastrodon which are a bother otherwise. Hp Ground is better against Heatran due to accuracy and hits charizard X, not sure if thats worth mentioning though. In Expert Belt's details mention that it can bluff a choice item, even if youre not physical. In BLue Flare's details mention how Fire Blast was nerfed to 110 BP but BLue Fire remains at 130 BP so it actually has a pretty big power boost over it.
Team options need a little, M-Blast is pretty obscure, and the ninetales mention needs to be changed to "solid on a sun team". ALso, mention Zard X as a teammate, it's pretty cool because like you said Special Victini can lure in physically defensive stuff and hit them for good damage. Zard X takes advantage of that quite well. Imagine that your opponent's best Zard X check is physically defensive Hippowdon and it gets blasted with Blue Flare, or Azuumarill with Thunder. Lucario is dead so remove that. Change Tyrantrum to Tyranitar, Tyrantrum couldnt be anymore irrelevant.
Trick Room Sweeper
Call it that. Other than that take the above into consideration for this set, it looks pretty solid otherwise.
Other Options
Take out that which was upgraded to "moves" or a slash on a set. Add some useless offensive options like DAzzling Gleam, or Shadow Ball here too.
Check and Counters
Look fine but add Charizard X, mention all pursuit users and how they can be a bother in one way or another. Also super effective priority like Mawile's Sucker Punch and Azumarill's Aqua Jet.
Makes these changes and I will stamp this bad boy.