I don't understand the logic here, you say that they don't vary in size but you do admit that we don't see the "full scope of dreams beyond the Future Dream".
In other words, you admit that the Future Dream is the only one who's shown to have universal size but rather than assume that it is simply larger you conclude that the others must be as large without evidence?
Similarly, you agree that not all paintings in Mario 64 have stars but... You insist that they must all be star sized? That's not very good logic either. It makes more sense that not all paintings are the same size as they depict different landscapes. Likewise it can be concluded that certain dreams are bigger than others as they are shaped by the subconscious mind of whoever is dreaming.
This is not how language works. Baseball Bat isn't the animal Bat, again. A dimension being used to mean universe in Super Paper Mario doesn't mean everytime it's used in other games it means universe. And Mario Party 5 primarily uses "World" to refer to the dreams again.
1) This doesn't mean they are universal just that the are other dimensions
2) This isn't how language works, the word dimension can mean several things under different context. Just because Marvel uses dimension to mean universe often (More than any verse I know) doesn't mean all dimensions in Marvel are universal in size)
3) One for the former. Secondly the existence of stars in a realm does not prove they are universal in size. The existence of Pocket Dimensions disproves that.
4) Time flowin differently in a dimension doesn't make it universal in size. Time is not a factor of space.
What is this strawman, nowhere is that implied. You are taking what I'm saying massively out of context
My general notion was that, we don't see the full size of the dream because the game focuses on a small part of dreams and the same premise applies with Mario 64 as well, where we have worlds in paintings that contain stars, however, we don't see stars in all dreams despite characters mentioning stars and the likes
Secondly, I never did say stars don't exist in the paintings, what i DID say was that not all realms SHOW the stars despite the fact we have characters mentioning starry skies and the likes. I really don't understand how you got that from what I said aside from twisting it around
You do realize that dreams, that otherwise wouldn't have a reason to be about space, contain them. The biggest example is Luigi's in Dream Team, this is further evidence that the cosmology of a dream isn't exactly depend on the dreamer itself as opposed to the main theme of the dream itself
Regarding your other points
1) Nothing suggests Dreams are in other dimensions, they are dimensions themselves and this is explicitly stated by Zeekeeper and other guides such as the ones Blaze posted here
2) Okay, so even by contextual standards, you are still basically wrong because in the context of them being called dimension, all of this literally was in effect and applying even to that context. When Luigi and Mario were traveling through dreams, it's stated that there were traveling between dimensions and we see them traverse space-time as well
3) We have guides use dream and universe interchangeably though, added on with the pointed out evidence I mentioned, I fail to see a proper refutation here
4) I literally never implied it does, but added on with the other evidence, it further supports my notion
