Can Ranmas curse be cured?
Yes. In one episode, Ranma obtained a mix that turned ordinary water into “man-drown-spring” water. The water effectively cancelled the original curse, so Ranma didn’t change when wet (unfortunately, the mix was a cheap imitation that only worked once). It is assumed that if Ranma were able to get to Jusenkyo, and find the real “man-drown-spring”, he could remove his curse.