Hello guys. This is made particularly for a fellow Rogue within the guild, however of course, anyone feel free to leave some feedback or something as well. Without further ado the "ability by ability" rundown.
1) Premed (12-10 seconds before pull)
2) Slice and Dice (2 seconds before the pull)
3) Opener Macro (First usage, 1 second before the pull. Handles both Prepot and Vanish)
4a) Legendary Ring (If you control it)
4b) Opener Macro (Second usage, as soon as you're in melee range. Handles both Shadow Reflection and Rupture)
5) Shadow Dance + Ambush spamming
6) Ambush spam while maintaining SnD and Rupture on target, and otherwise spending CPs on Eviscerate. Also use Preparation without capping energy during Shadow Dance (generally after 2 ambushes or so).
7) Around 3 seconds before Shadow Dance ends you want to fit in both a Premeditation and an Ambush. How easy this is will depend on primarily the pull timer provided, and how early you cast your first Premed. If you can only do one or the other, Ambush is of a much higher priority.
8) After the Shadow Dance you want to pool as much energy as you can before either capping energy, or right after you reach 5CPs. Once either of those conditions are met use Vanish again and immediately dump the CPs into an appropriate finisher. Optimally you want to avoid having to refresh Rupture before casting Ambush, as that wastes 5 seconds of the Vanish cooldown reduction from our 4pc. Hopefully you'll be able to cast 3 Ambushes from pooling your energy before the Vanish, but you should always expect only 2, making sure that you use your last Ambush at end your Subterfuge window, provided that you are using Glyph of Subterfuge (which you should be). I'll be going more into this Vanish usage later as it can be fairly tricky.
And that's pretty much it. After your Subterfuge window is up you go to your normal rotation of only casting Backstab to avoid capping energy, refreshing Rupture and SnD when needed, and primary using Vanish on cooldown. The only times you wouldn't use Vanish on cooldown is if either Shadow Dance by itself is up within 6 seconds (in which case you save the Vanish for the damage increase provided by the 2pc), or if both Shadow Dance AND Shadow Reflection are up within 12 seconds (which again you'll save Vanish for).
Here's where I rant on about the 2nd Vanish usage. It's confusing as hell as to how it plays out because it depends so much on how your opener up to that point went. Optimally you want to cast your 2nd vanish at around 60 energy, at a max of 3 CPs (optimally at 2, so you can immediately Ambush right afterwards to get Find Weakness back up), without casting Rupture or Eviscerate beforehand, and Rupture is just about to need to be refreshed but it's not exactly there yet. While I wouldn't say this rarely happens, there are just a lot of things that can fuck you over. A lot of situations I've seen involve Rupture just about to fall off due to excessive multistrikes, causing me to have to cast Rupture right after I vanish instead of Ambush (which isn't that bad since Rupture doesn't benefit from FW anyway). A few times I've had 5 or more than 5CPs, in which cause I have to either make sure I can both Vanish and dump those CPs before HaT gives me another CP, or even just having to dump them before the Vanish (which blows, though keep in mind refreshing SnD doesn't affect the Vanish CD whatsoever). Sometimes both have happened! In which case I just cry in a corner and have a meltdown. Outside of the optimal usage of Vanish there isn't a strict answer I can give to you. Instead you just have to keep in mind that...
1) Vanish gives you 5CP with the 2pc. Under no circumstances should you cast Vanish at 6CPs or more. You may cast at 5 however if you are able to track HaT fairly well.
2) Rupture and Eviscerate, when cast, remove a second of the Vanish cooldown for each CP used. So pretty much, 5CP Ruptures and Eviscerates shave off 5 seconds of the Vanish CD. As such making sure to cast Rupture and Eviscerate only when Vanish is on CD will simply lead to move Vanish usages during the fight. Slice and Dice doesn't have an effect on this whatsoever so refresh it whenever you want yo.
3) You OPTIMALLY want to either start your Vanish/Subterfuge window with casting Ambush, or casting Rupture/SnD into Ambush. Opening the window with an Eviscerate is strictly worse due to it not benefiting from Find Weakness. However if you're at a situation where you IMMEDIATELY need to dump CPs, and neither Rupture nor SnD need refreshing, just bite the bullet and open with Eviscerate, as overcapping CPs is much more of an issue.
Finally here are the macros I use regarding my opener.
/castsequence reset=10 Draenic Agility Potion,Shadow Reflection;
/castsequence reset=10 Vanish,Rupture;
#showtooltip Soul Capacitor
/cancelaura Spirit Shift
I've gone back to just having one opener macro button that needs two keypresses. The last 2 macros are kinda relevant to the opener, but are mostly just general.
And that's pretty much it. For a visual guide here's a video of me rambling on about the opener.