For all we know, based on what we've been shown, that bowl only covers the Other World, which Goku stated has no time, so it's one big spatio-dimension.
Source?
That's not what means. Outer means outside of and external. It's a bowl outside of the dimension, we can clearly see that. That does not mean it's outside of dimensionality, that's actually r-word (I can't say that).
No it doesn't. That's like saying a barrier has to be fourth-dimensional in order to hold a universe sized spatio-dimensional. It doesn't, it just has to be an even larger 3-D structure, stop being stupid and/or cherry-picking.