Okay, I'll post my opinion as I read the blog.
I feel like a single universe seems okay for
Low 2-C.
There is a statement of countless universes within chaos, so that would be
2-C/2-B as you mentioned. (More likely 2-B)
I disagree with Chaos being 5D. While it is indeed the source of everything, and you need its energy to "transcend the universe", I feel like it's made pretty clear that it is to go
outside the universe. They can leave the space-time continuum of the universe they were in and enter the Void, but I doubt the Void can be seen as a "significant" 5D space. Some staff members could correct me if I'm wrong.
I think if you can prove the Void is infinitely large, that would be better for your case. There is also the mention of "infinite energy" but that doesn't tell us much about the size itself since you're arguing for "higher size" in the first place.
I disagree with your evidences for "infinite universes". "Endless territories" can be seen as the same as "countless" universes you mentioned before.
The Great Universe seems to be higher into
3-A (for the spatial component, but that's not too important, I'm just rambling)
"Limitless time and space" seems interesting, but wasn't it about the guy who fled from an attack and went through several time and space? I remember something like this.
As I said, I agree with the
2-B rating, I disagree with
Low 1-C, however.
I disagree with the Low 1-C for Part 5. It seems to me, it's just a "higher" and "stronger" world, I don't see anything that might hint as the realm being "infinite bigger" or infinitely more powerful than the ones below. Technically, even if that was the case, that wouldn't be enough for Low 1-C too, I feel like.
Source Sea MIGHT be
Low 1-C, at least I can see the possibly.
I don't see the Boundless Sea/Infinite Sea as higher, personally, the evidence feels lacking. I find the feat regarding "building a stairway using space-times" interesting however.
Is the Void Region encompassing all "eternal" seas? If so, I could see PERHAPS higher into
Low 1-C, like +1D.
I could see a potential +1D for Eternal Controller, but absolutely not High 1-B. The fact they can still die from a timeline destruction is just too much of an antifeat.
----
As for the blog itself, it helps A LOT comprehending the cosmology, but there is a lot of unnecessary stuff. Do you think that you could reduce the amount of text?
Additionally, sometimes, you claim something, like "the universe continues to expand constantly, albeit slowly" without any scan, yet, you put the scan that explain such things later in the blog, so I feel it is confusing.
Also, I think you should change a bit the layout of the blog. For example, I don't think part 1 is necessary, you should directly start with part 2 (regarding the structure of a single universe) and then, maybe, mention some stuff regarding the Monster Dimension if you wish.
Basically, try to modify it so that everything is simple, concise and anyone reading it (without any knowledge of the verse) would understand it.