I suggest:

1) Use the Greek legend idea, and research it. It'll add interest to 
'just another Ranma fic'.

2) Drastically simplify your new characters' bios - or, at least, what 
you use of their bios in the first story. If their stories are so 
important, why are you writing a story about Ranma? Why not just write a 
story about them?

3) 'Midknight' needs a new name. Jay, Ed, and Sam are ok, but a little 
everyday...

(well, you asked for advice... and of course free advice is worth what 
you pay for it...)