try the ranma crossover archive at fanfiction.net
Yes. Ranma and Shampoo in Shampoo's Red Thread of Dread and Earth of Shampoo - Episode 13 - Shampoo and Ranma animals friends everywhere! your love life are ever had.
Try fanfiction.net
In episode 15, though technically Ranma had met Shampoo in China before when he and his dad was training before coming to the Tendo Dojo but she makes a reappearance in episode 15, looking for Ranma now.
Episode 15.
http://anymanga.com/ranma :)
Shampoo makes a re apparence at the end of the first season, she bursts in the house looking for Ranma. In the manga, Shampoo doesn't appear until Volume 4. So the Anime put her in early, if that helps the confusion. Though. Ranma met her once in China before coming to Nerima being the reason she is hunting him down in the first place.
you can read it on the internet under 'Ranma Manga'
No, Ranma and Akane never 'officially' get married, but the closest they come to is in the last volume of the manga when they do get ready to do so :). The manga brings more closure with the two characters than the Anime did, so I suggest to read it because of Ranma's final HUGE love confession in the last volume :).
That sounds like the first episode from the OAV Shampoo's Sudden Switch - The Curse of the Contrary Jewel.
If you mean read it online bleachexile.com
I don't have the ability to read fanfiction, but there are many great Spuffy AU fanfiction stories available online. Websites like Archive of Our Own or Fanfiction.net are good places to find new and interesting stories to read.
fanfiction this website has a bunch! I would like to say one thing.... you know she is a hunter now? and hunters don't have romances..... but one reason fanfiction is nice is because it can have parallel universes!