One mistake:

    Sylia tried to repress her laughter.  "Well...the one with the 
pigtail's Nodoka Hibiki, Ranma's grandfather. 

Obvious ain't it. 

God, how could she live like this?  Watching for rain, being extremely careful >with every drink in her hand...

And that scene where Priss walks into the rain, and Nene standing in the doorway too. Ranma should introduce her to Ryoga, now there's a guy who knows how to avoid water. 

"Been long time I do that," she said contentedly.

Try ".... I _no_ do that."

    Ranma just rolled his eyes.  "Oboy...Have you learned the Kashuu 
Tenshin Amaguriken yet?"

Just to be sure, do you know which move that is? Another writer got it wrong, just making sure you're not making the same mistake.

And I forgot to ask you something about part 3, please clarify how Mackie knows Ukyou well enough that she stops by to talk to him.
And I see that the new hardsuits are waterproof. 
I normally don't read BGC fics, but this one caught my eye. Good job.