Got the series I know how it ends, and that is really all they have going for them...the fact they are cannon.
You obviously haven't seen how the manga ends, Beer-monster.
Ranma and Akane may love each other (as much as two sixteen years olds can) but it will end in tears, As things stand they CANNOT be happy together... there are somethings that love can't conquer.
Similar arguments stand for all the fiances...however I think R&A have the deepest and most complicated issues with the most hurt involved.
Of course that is the fun of fanfiction. A truly convincing Ranma romance that is not too waffy, is well rounded, or does not rely on the bastardisation of the characters...that is the holy grail of Ranma and probably all fanfiction.