From pure power standpoint, I'd say Goku has the edge. However that doesn't take into the account all the special powers that characters in destiny have. For example Crota is normally immune to all damage without one of the knight's swords, but it shouldn't be too hard for goku to get it. You also have to keep in mind Goku's nature. Sure he could just destroy planets, but he never would because that would go against his morals. Defeating Cabal and Vex wouldn't be hard for him. However hive on the other hand, who knows what kind of craziness they have in store. And for the guardians, I don't think they would be any challenge to goku, but he also wouldn't really try to kill them either.