Preface: Your spreadsheet wouldn't let me fill it out, so I can't use it. :/
For ground floor bosses you can just have everybody Savage Blade or go with same SC element as Savage Blade(Fragmentation/Scission) every boss, since there is no WS Wall.
For Ground floor my 8-boss group does:
RDM: Savage Blade
BRD: Savage Blade
COR: Savage Blade
GEO: Judgment, Dagda on B/D
WHM: Mystic Boon
WAR: Fimbulvetr B/C/D, Impulse Drive A
For Basement my 8-boss group does:
RDM: Black Halo E/G/H, Imperator F
BRD: Savage Blade E/G/H, Rudra's Storm, Mercy Stroke F
COR: Savage Blade E/G/H, Evisceration F
GEO: Judgment E/G/H, Dagda F (and Dagda on H at his own discretion)
WHM: Mystic Boon E (doesn't melee other bosses)
WAR: Fimbulvetr F/G/H(alternate to Resolution for G and H if Darkness is possible, except for if H has done Flaming Kick/Fulminous Smash), Impulse Drive E
As far as making wrong Skillchains goes, it only really matters for A/E, or if you are pressed for time on other bosses. A heal slipping through on BFCGDH doesn't impact the fight too awful much if your DPS is sufficiently high(And if you have consistent procs rolling on Aita). I've had embarassing days where I've healed Aita for 99k, and no one batted an eye about it, because we killed it shortly after.
All in all, as far as H boss(Aita) goes, he leans towards being more friendly toward Light and Wind adjacent Skillchain properties.
Firstly, he has no Wind mode, meaning Detonation will never heal him. He also has no Light mode, meaning Transfixion will never heal him. He also has no Darkness mode, since if he uses his one Darkness TP move, it means you hit Enrage and are dead (So effectively, Compression will also never heal him). 3/5ths of his stances lean into the Darkness side of things, 2/5ths in Light side of things. This means you have to pay attention and alter what WSes you do, if anyone is doing WSes with different SC properties. You should note that most strategies for melee for him involved everyone simply resorting to Fragmentation based SC property WSes, such that no SCs ever get made, and WS wall is avoided. If allowing anyone in your group to open or close skillchains, even incidentally, they need to know what they're doing.
The long chart you have at the end there, for instance, showcases incomplete skillchain consideration for every boss and skillchain set.
You have to know Level 1 Skillchain interactions, too, as Level 1 skillchains still carry a single element, and as such, can still be absorbed by the Sortie bosses.
A/E - No Reverberation, Distortion, or Darkness. Reverberation is Water, no Water damage. Water damage is what causes his Enrage, which is that his next TP move will deal damage proportional to the amount he absorbed (generally 99999, unless a VERY SMALL amount was absorbed(sub 1500)).
B/F - Wind Mode: No Detonation, Fragmentation, or Light
Thunder Mode: No Impaction, Fragmentation, or Light
Detonation will not heal him during Thunder Mode.
C/G - No Compression, Gravitation, or Darkness
D/H - Flaming Kick: No Liquefaction, Fusion, or Light
Fulminous Smash: No Impaction, Fragmentation, or Light
Eroding Flesh: No Scission, Gravitation, or Darkness
Icy Grasp: No Induration, Distortion, or Darkness
Flashflood: No Reverberation, Distortion, or Darkness
For H in particular, this means that typically you can get away with introducing Tachi: Mumei or Fimbulvetr without much issue since they carry the SC properties of Detonation/Compression/Distortion. As already stated, Detonation being made will never heal Aita, and Detonation opens for Scission or Gravitation, meaning in 4/5ths of his modes, resulting SCs closed by Savage Bladers or Black Haloers or another Mumei/Fimbu will only result in dealing more damage rather than healing him. If in Eroding Flesh mode, Fimbulvetr/Mumei are still on the table, because they will close Distortion from a Fragmentation primary WS, which will result in more damage done to the boss, without healing it. Of course, in practice, it's best to hold off on doing Fimbu/Mumei during IcyG/FlashF, since they can close Distortion and heal it, those modes are when you rotate to Resolution or Tachi: Kasha(but as a result of you being the closer in that case, you can wait and still do them, if another SC gets made somehow). This applies to Maru Kala from the Hand to Hand as well, with alternate WS being Dragon Kick or Victory Smite.
Looking at other Prime WS for H, you can look at the commonly built Foenaria. Foenaria carries Induration/Reverberation/Fusion. It will open and close Light with Savage Blade, making it ideal for 3/5ths of Aita's modes. It also closes Light off of Black Halo, while opening for Compression for Black Halo. As well as opening Impaction for Judgment. Basically this means alternating to Cross Reaper if he does Flaming Kick or Fulminous Smash. This applies to Terminus for Gun, where RNG or COR would alternate back to Savage Blade where DRK is alternating to Cross Reaper.
Looking at Disaster, Dagda, and Sarv, they are Transfixion/Scission/Gravitation. This makes them a little awkward because they open for Distortion for Savage Blade to close, and repeated use makes Darkness off of Distortion. Done after Savage Blade and they make nothing. This means Disaster/Dagda/Sarv want to avoid WSing during 3/5ths of Aita's modes, unless they know they're going after an SB, and that the mode is going to change before the next SB goes off. This means that Disaster/Dagda/Sarv cause Savage Blade to be a closing liability in 2/5ths of Aita's modes as well, which is somewhat bad for business.
All in all, a lot of times, simultaneous WS firing or WSing so fast that the chain window is avoided can give you the appearance that you're doing things right, since things aren't going wrong. A lot of times, that's how people make it through stuff in this game lmao!
All of these considerations are generally why a lot of groups sport a PLD nowadays, even if they're not doing 9-boss comp, because you can avoid almost all of the mode changes by keeping him in Frog-Kited limbo (not too mention avoiding a lot of the damage). If you really wanna bring your friends for a "casual" 8 boss run, get a skilled PLD to kite most of the bosses for you, and remove most of the margin for error!
