Thank you for that, it has helped a lot in working out what you are going for.
I do have some concerns though, assuming I have understood everything right.
First, Rallying Cheer and Golden Arm. They convert stacks of Scored into their respective buffs, but is this continuous whilst Rallying Cheer and Golden Arm are in effect? So, as an example, if I have 2 stacks of Scored, then use Golden Arm, I now have 2 stacks of Golden Arm, If I continue to use Weapon Skills, does this also increase my Golden Arm stacks, automatically converting Scored into Golden Arm?
If so, how do Golden Arm and Rallying Cheer work together? Can they be used together? If I have 2 stacks of Scored, use Rallying Cheer, then Golden Arm, I will have 2 stacks of Rallying Cheer and Golden Arm will be in effect, if I then use a Weaponskill and generate a Scored stack, where does it go?
This then ties into Blitz Ace and it's variations, can it handle that system?
Also, as an FYI, 0.2 seconds off per stack is insane, at 5 stacks that is a GCD of 1.5, the lowest the game can handle and trust me as a Monk user at the start of SB, that sort of GCD shift can be quite jarring.
I now want to address something that could be a concern, With Grand Slam being so powerful (1600 potency in total), I do think it ruins what you intend for the rotation to be. I think you intend Blitz Aces to be used at 5 stacks, once you use them 3 times, you then Grand Slam as a high potency hit. However, with Blitz Aces being static potency per stack, it does cause issues, which I do want to highlight.
First, if we go by your intended solution: Build to 5 stacks, use Blitz Ace, repeat until Grand Slam, I calculated the total potency to be ~3540 potency over 16 GCDs, which is an average potency of 221.25 per GCD.
Compare this to 2 different situations of Blitz Ace that I calculated.
This first one assumes you can use Blitz Ace back to back for 100 potency each (more later), so that is 3 Blitz Aces at 100 potency each, then followed by Grand Slam for 1900 potency total or 475 potency per GCD.
However, upon more careful reading, Blitz Ace puts you at 1 Stack, but it is a weapon skill itself, so does that give you another stack, meaning you come out at 2 stacks? That is 2200 potency total or 550 potency per GCD.
However, I also considered that the Blitz Aces 'leaves you at 1 stack' IS the '1 stack generated by a weaponskill', and since you need more than 1 stack to use Blitz Ace, you need to use at least 1 extra GCD between them, using the weakest combo GCDs to get 3 Grand Slam Stacks, you get to 3140 total potency over 7 GCDs, which is ~448.57 potency per GCD.
I think it highlights a fundamental flaw in the system, considering we are looking at potencies more than double what I think is intended and even if we bring things like Venom Shot etc. in, it isn't going to help things. Ultimately, there are 2 things causing this, the insane power of Grand Slam compared to the rest of the kit and the ease of getting there via easy to use Blitz Aces. Now, since I think I know the intent, I think there is a simple fix, make the scaling on the Blitz Ace potency non-linear, that is, the more stacks you have, the more potency each one is worth.
As an example, take Bard's Pitch Perfect. At 1 stack, it is 100 potency, at 2 stacks, it is 220 potency, with each stack being worth 110, at 3 stacks it is 360 potency, with each stack being worth 120. As you can see, as you stock more and more stacks, the relative potency increases, meaning it is worth it to save them until 3 stacks. However, you can still use them at lower stacks, which you would do just before you go into the next song.
I would also say the potencies for Grand Slam and the full powered Blitzes are too strong with how often it seems you will be using them. They are 500, 1000 and 1500 potency in order of power at full strength, that is a massive disparity between them. Rallied Blitz Ace is 3 times as strong as Blitz Ace and 1.5 times stronger than Golden Blitz Ace, just to put them into perspective. At most, I would put them at 500 potency between the strongest and weakest ones.
I also find it weird thinking that Scored is being used for both self buffs (Golden Arm and Rallying Cheer) and the Blitz Aces, but I can also see you get quite a lot of them. I haven't done any working out on how many you get and whether you get enough etc. as I haven't gone into THAT much detail, just those 2 things above really stuck out to me as potential problem points.
I will confess, a Blitzballer job doesn't interest me, but I am hoping these things I have pointed out might will help you to refine your ideas, or you might turn around and say I have misunderstood something, of which I am happy to be corrected. It does seem to be a more unique take on a job though.