everything has a cardinal direction, even rooms have it
Being the universe in reverse means nothing much to this, i can as easily say that being small is also part of the "universe in reverse part"
yeah, but that would not matter much unless it is universal in size
aka physical travel
yeah, it is also stated to be another apace time directly, but again, that doesn't matter unless it is universal in size, which would bot be even if it is 1/10 of the afterlife and living world combined
Yes, another dimension, the problem here is again the size
that is headcanon, it doesn't need a size to withstand their blows, it simply needs durability, plus the dimension was quickly destroyed anyway so it didn't really withstand it, it is another space time tho, i will give you that
The dimensional barriers are the fabric of space time, they are not low 2-C, they 2-C via separating 2 universal space times, if you are saying that the barrier is low 2-C then the 2-C ratings make no sense since they are based on the barrier being 2-C
And it was also shown to be small in the db anime, plus when was it stated to be a universe in the manga?