Yeah, Frieza was in a Hyperbolic Time Chamber, which either counted as a different dimension or the dragon couldn't take that into account. Or Frieza...
the feats say otherwise. until we get goke and geets throwing hands with beerus using their new forms, we can't say they how strong they actually are...
They re did the beginning because they didn't have the rights to the first movie for whatever reason if you ignore that every thing else makes sense...