I personally would increase the level cap to 100 and focus on finishing the rest of the map and quests. Then adding super saiyan 2, adding super namekian (Something like a super saiyan but for namekians), adding the super buu transformation that will be before the kid buu one. All of these transformations would make the game more interesting.
Adding new skills ofcourse because of the level cap increase (Dragon Fist,Spirit Bomb,Light Grenade).
Also it would be nice if we could charge the kamehameha or other abilities for how much we want but that there is a point where the attack is at maximum charge. The more you charge the stronger the attack gets. It has an advantage and a dissadvantage. The advantage is that it will help you out tremendously but the disadvantage is that you will be vulnarable to the mobs. Ki clashes would be nice too! One more thing the kaio-ken should increase the flying speed too! This is a suggestion I have a feeling that all of this will never happen but I still have some hope for atleast new transformations in the future. Tell me what do you think?