Kanzenshuu

It seems that beetween Buu saga and Ressurection of F saga is like 5 years break right?

Is 5 years enough to make Mystic Gohan unable to even SSJ2? While 5 years was exactly the time between Cell Game and Broly's Revenge, Gohan had no problems to turn into SSJ2 again, weaker yeah, but still.

Why ...

Why Gotenks SSJ3 is only 4x stronger than Goku SSJ3, while they were able to hold on SSJ3 like 20x times longer , actually, only the fusion time itself was the limit for their SSJ3 form?

Also, Gotenks was able to delete Super Buu like 4 or 5 times without problems + showing off, while Mystic Gohan ...