Franklin Richards at full power will possess telepathy and telekinetic powers stronger than those of Jean Grey and Professor X. He can create pocket universes in alternate realities. He has precognitive abilities, can see the future. Simply put, when all the non-mutant Marvel (except Scarlet Witch) "died" facing Onslaught, Franklin created an entire Earth that was on the opposite side of the sun and sent all of the heroes there. This world included six billion lives that he made, and the best part, is that he did all of this subconcsiously!!! The Celestials were scared of him. Did I mention that he did all this when he was six.
Franklins powers in my view were a bit exaggerated. I seem to remember (vaugly) Franlin getting killed by a sentinel (wich had protection from his powers). Also hyperstorms powers were greater than his. Prof x and jean i think still edge out franklin (look at comics in other time lines). Scarlet Witch is a mutant (?) i thought she was the daughter of magneto. As for the pocket universe, it was a small ball which franklin carried with him