yes it is another dimension, has a location, a separate space-time?no, and again, kaio sama was SLEEEEEEEEEEEEEEEEPING, so his ki was lower, while the new namek planet had plenty of people with a power level comparable to him, actually they were to many people, how could goku not felt that if he can in "another"dimension????????????????????????????????????/
yes it does, actually there is many proof for the afterlife being just another location and not a space-time separated place.
you know how many times it was bringed up the fact that the time in the afterlife flows the same?you know that goku literraly falled into hell just through the clouds alone?(yes that happened).
ok