@streak619: Sure. I'll just list the ones from your opener and not all of the ones throughout the entire debate though because that's way more time and effort than I want to spend on this. Keep in mind I'm not a Big G expert so it's possible everything I'm about to say is totally wrong.
Your hax section is fine so really it's just stuff from the destructive power section.
or starters, in Annihilation #5, he was able to cause an explosion that encompassed three star systems:
In Thanos Imperative: Ignition, however, it was retconned to be galactic in size and power:
I'm skeptical that this is actually stating that it's a galaxy sized blast. The actual statement in the scan is "The annihilation wave was obliterated and the galaxy swept clean". To me that's simply stating that his blast swept the galaxy clean of the annihilation wave, but really that's not the main thing I care about and I could easily be convinced otherwise.
The more important thing is I think the blast itself is very overrated in terms of potency. Maybe there is an argument for it being galactic in size, sure, but the way you used the feat you seemed to be suggesting it was equivalent to a true galaxy busting attack. If I'm wrong about that please let me know, but that's how I interpreted it, and I think it's disingenuous to use the feat that way. Like a couple of pages later in the issue we can see that the blast itself didn't even completely destroy the annihilation wave's ships, Annihilus survived it, and Nova survived it and protected his allies from it with a shield.
And I highly doubt you would say that this means they have galaxy level durability.
So I suppose you could use this feat to show that Galactus can output really large AOE but... what would be the point of that then when the potency of the blast itself isn't that strong? It seems at worst you're misrepresenting the strength of the attack, and at best you're just throwing in a feat that doesn't really matter when you're trying to argue universal DC capabilities.
Moving on, in Cosmic Powers #6, a hungry Galactus was able to stalemate and even overwhelm Tyrant, a creature of his own creation, in a battle that destroyed galaxies:
Maybe I'm just nitpicking with this one, but the problem is this isn't the case of your standard omniscient narrator saying that galaxies were destroyed in the fight, it's actually Thanos speaking and he says "The enmity raging between them must have destroyed entire galaxies". I really do think that's a important distinction to make note of, because Thanos is just making an assumption based off a small snippet of a fight he's watching on his screen. He doesn't actually know if they destroyed galaxies or not, he's just assuming that they did based on how powerful he believes Galactus to be. So again maybe this just sounds nitpicky because it's very likely that galaxies were destroyed in their fight, but I don't think it's fair to just outright claim it as a fact based off of Thanos saying "yeah it might have happened" (and then fail to mention that this is the case).
Despite being hungry and deprived of a real world. A hungry Galactus performs a similar feat yet again against Agomotto in the latter's dimension, where the mystic vibrations of their battle wreaks havoc across many dimensions:
I'd just like to point out that you actually didn't post the scan where it's stated their fight was causing damage across multiple dimensions, lol. I reread the scans you posted like 4 times and it confused the hell out of me until I checked the issue and saw that it was on a later page.
That's righ folks, not even their actual attacks or the clash, but merely the vibrations from it were travelling to the dimensions of the other entities of the Vishanti and wreaking havoc.
I think you're overselling this point. What exactly do you think causes surrounding damage in a clash? It's the vibrations (mostly appearing as shockwaves) from it. You seem to be suggesting that this is an insane feat because vibrations must only be 0.0001% of the attacks power or something along those lines to try and make the feat seem more impressive, and I don't think that's a very strong argument, nor a necessary one when the feat is more than good enough taking it at face value.
Galactus has also used such scales of power in combat, such as when he oneshotted a celestial, a nigh universal entity, and then went on to tank the combined power of the three of them:
Celestials are not nigh-universal in any sense barring a few extreme outliers, and these mad celestials were not in this issue. Just a few pages after their combined form one shot Galan, they attack the F4. Thing tanks a blast for an extended period of time and survives unharmed, Sue blocks that blast for an extended period of time and then easily breaks through the armour of one of the celestials, Johnny with the control rod effortlessly blasts off one's arm and then survives being blasted in the back by another, and all three blast at once, breaking through Sue's shield and directly hitting every member of the F4 almost point blank, and none of them are harmed further than simply being KOd.
Now either I missed a massive amount of context to this issue or this is actually a low end feat Galan based on how the Celestials did against the F4 in this issue. Also maybe semantics but Galactus was straight up one shot by the combined Celestial. His body survived but he had to be either revived or at least woken up by Franklin. I'd hardly call that "tanking".
Which is actually quite impressive because not only were the three gods born of the energies of the expansion of the universe and the Big Crunch but can also use its power in combat:
So to be able to be capable of killing all three in gods like Galactus is explicitly painted to be is impressive in and of itself because these three gods could all-in-all tap into multiiversal amounts of energy.
I know I've talked to you about this before, but being able to use some fundamental type of energy that's present throughout the universe or multiverse does not mean they are universal or multiversal unless they are explicitly shown being able to manipulate it on that scale, which I don't recall Tenebrous and Aegis ever doing, and I find it highly unlikely that they were that powerful when Surfer survived a beating from them and then later killed both of them pretty much instantly by tapping into the Crunch himself.
If this isn't enough to show that Galactus is atleast universal in raw energy, then how about the fact that his very origin consists of universal feats? Galactus survived the destruction of the previous universe by fusing with the previous Eternity, the sentience if the universe, as well as the following Big Bang of the new universe:
Uhh Galactus was reborn in the new universe. It literally even says he was recreated in the databook that you cite immediately after this lol. This isn't an applicable feat.
Multiple universal feats right there. A last piece of evidence to support the notion that Galactus is indeed this powerful would be the fact that even databooks support Galactus being universal:
That databook also says Thanos is universal in scope. The thing is universal in scope does not equate to universal DC/Durability and whatnot. When that particular databook you're referencing (Heroic Age: Villains) talks about scope, it's just talking about where the villains can operate and effect. So for instance Absorbing Man is National (because he stays in the US) but Deadpool is interplanetary because of the shit he gets up to.Clearly that does not mean Deadpool is a planet buster who is hundreds of times more powerful than Creel. Or as another example Kang is listed as multiversal in scope, and you obviously wouldn't call him multiversal in terms of power.
Anyway, good work overall. This was a fun debate to read.