Hmm....Let's see...Well: 

Ryouga would probably want some way to end his directional curse: So his
power might be to go exactly where he wants to instantly. 

I think the main problem with developing powers for a lot of the ranma 1/2
characters if that, if we go by the assumption that the cower would react
to some personality trait or desire, then you risk invalidating certain
parts of them that make them entertaining. 

For instance: Among akane's subconscious desires would be the ability to
fight as well as ranma. It she got that, however, then ranma wouldn't have
to save her anymore. There is always the option of flawing the powers: 

For instance, say Ryouga gains the ability to teleport: However, it he
tries to use it to cover long distances, it becomes about as reliable as
just walking there. 

Just a couple thoughts

~Eimii- professional pain magnet