all of those are true, but some can be explained
Nameks can eat for the hell of it.
Goku did not last very long on his first trip to the time chamber, and only the field after the chamber doors had the gravity effect.
android 18 was likely caught off guard.
Goku got a zen kai, Cell was not at full power, he did not have an aura. Pikkon is amazingly powerful.
the z fighters had little to no knowledge of anyone stronger then freiza prior to cold. Freiza himself constantly said he was the strongest. purely out of ego
I dont think it was ever said Kid buu was the strongest buu, Maybe the strongest in the buuvolutions that did not involve absorption.
You cant die in other world, but obliterated out of existence by super natural creatures like buu, a whole nother story.
as for the bodies. Those episodes and the other world tournament were filler episodes. Not apart of the main story line or considered cannon.
---------- Post added 2012-09-09 at 03:45 PM ----------
as for the saiyans breathing in space. I simply assume its something they can do temporarily, but not for long periods of time. Unless you are broly i dont think the legendary form requires air to exist.
---------- Post added 2012-09-09 at 04:26 PM ----------