Ok, let me try and address all your points:
Having designs of chandeliers doesn't even mean you understand them. Printing something out doesn't mean anything of what you implied, anyone can print anything out. Calculations and blueprints for almost any shape are easily found online, I mean just because I 3d printed a spaceship doesn't mean I know how to build it.
Yea, almost definitely someone with photoshop knowledge made this, but why are you assuming that Roy's extra leg looks any good? Why do you think he's an amazing artist if you can't tell the detail at all because of the bluriness. I'll give you a point though, he made 7 new models and they look fairly well so he has some skills for sure. Let's add artist to the resume.
Ridiculous resume you've ever seen? Are you in high school? About half the people I know could make this leak in less than a week. That might be because I work in the gaming industry and half the people I know are artists, but what this should tell you is that it isn't a "ridiculous" resume, this is just general artist skill with time commitment.
You guys should keep in mind that even if this was real this was made by someone. So if someone exists that has the skills to do this then obviously there's people that exist that have the skill to fake it. Normally it isn't about "skill" it's about time commitment. People will waste weeks on something if they are getting paid, almost no one will waste days on something if it's just for a prank. It's never about "ridiculous skill".
The Grinch stuff is only relevant because it's something unique that throws you off, it doesn't prove or disprove anything. Basically it's a "who would think of that!" scenario, but if someone were to think of adding that then that whole theory falls apart.
You do realize anyone can look up names and companies online btw? Having a name on the paper doesn't mean it was truly that person that posted the picture.
Here's my other post in the general thread:
Behind Cloud there's 2 crystals, in one of the versions you can see one of the crystals sticking out between his legs, but the 2nd crystal is not viewable in any version. Then in the leak there's only 1 crystal instead of 2.
The whole island that disappears and that section of the waterfall that's curved, they are never visible in any past version of the mural, and thus they are completely missing in the leak.
There's a mountain that has 3 rays of light, Ray A is visible in one version, Ray B is partially visible in another version, Ray C is never visible. The leak has Ray A pretty accurate, Ray B is semi-accurate having a slightly different shape, and it has no Ray C.
There's a conglomerations of rocks behind Nana, Nana is one of that chars that has basically not moved at all so she's in front of those rocks in every version. In the leak those rocks are non-existent.
The things I am talking about are not "dark" or "light". The leak is outright missing parts of the stage. Missing crystals. Missing floating rocks. It isn't about it being blurry or not. The "light shaft" I am talking about is extremely visible, even in the leak, Shaft A and B and super visible, yet Shaft C (which should be literally right next to Shaft B) is non-existent (it's actually not even a light shaft, it's just light reflecting off water from the waterfall).
If you want to know it's the rightmost front-side mountain, right behind Dedede (it's actually not light, but water from the river). Also that same river is non-existent on the leak. On the leak it looks like a lake that ends as opposed to a river that falls off the mountain. And before you try to explain why that happens, let me tell you that curiously the "lake" portion of the leak is always visible in all previous versions of the mural, but the river portion of this same lake was never visible and coincidentally it's also missing from the leak even though the lake section is still there.
So like either they decided to cut/delete/change all the objects that have been located behind characters in all previous versions or a guy was just filling in the blanks with clouds and whatnot (or letting Photoshop fill it for him) and obviously couldn't guess when there was a river, an island, crystals or anything else.
I tried to prove this leak true. I tried looking behind every character to see if the leak matched and I didn't find a single instance of an object that was hidden behind a character that was also present in the leak. In every single case the objects were missing. What does Occam's Razor tell you about that?