You are right there is no ssj5 or 6, but you are wrong Goku does go ssj3 and ssj4 but trunks does not because he cant go past ssj3 since he wasnt born with a tail. vegeta doesnt go ssj3 but he does go ssj4 because he cheats and uses some invention to pass ssj3 and go to ssj4. thats db GT stuff, and the rest of what you said is true.