You'd be guessing correctly, although I changed a few things around.
Rachel is still a Dragonmaiden, but now Dragonians are akin to the Endless in Breath of Fire... basically, they can't die of natural causes and don't grow old, but can still be killed.
The Neko-ken training is going to take place as usual, but there's going to be... repercussions. That is all.
EDIT: This is the new background/plot I came up with for the fic.
Basically, shortly after leaving Tokyo, Ranma and Genma make their way to Hokkaido. There, in a secluded area where no humans dare venture, they find a village of... let's call them 'people' who call themselves the 'Dragonians' and refer to the surrounding area as the 'Dragon Nation'.
It is hinted there are more villages, but all of them are under the Earth, and that village is the only surface one. Most of the townspeople look human... if you overlook the Chinese dragon-style horns, patches of scales in various places of the body and slitted eyes. In other words, from a distance they fool most people.
It also turns out the Dragonians developed some powerful martial arts styles, and Genma pulls his patented 'sell Ranma for stuff' thing, requesting scrolls and food in exchange.
Only, things don't quite go as planned, and Genma finds himself unable to 'recover' Ranma for the time being. During his stay in the Dragon Nation, Ranma grows close to Rachel Feobane, the daughter of the 'God Dragon-Empress' Serina Feobane.
Rachel is a half-human, half-dragon, or 'Great Dragonian', a hybrid who meshes the best of both worlds and is able to shift form between human and dragon at will. The human-looking Dragonians are all Great Dragonians, whereas the dragonic-looking ones are regular Dragonians.
As you guessed, Empress Serina has dragonlike features, while her life-mate, or
zin 'na, is a human who, for some odd reason, is in love with her.
A couple months pass, and Rachel asks Ranma if he'd agree to be her life-mate. Not really understanding the meaning (Rachel assumes Ranma is as mature as ythe average Dragonian child, while he's not - a honest mistake), he agrees, and through a certain ritual, a part of Rachel's soul is bonded to his own, linking her to him.
However, just about at this time, Genma manages to spirit Ranma away. Rachel wants to go after him, but... unforeseen circumstances (hint hint) cause her a trauma, and while she's recovering, Genma and Ranma leave Japan.
Cut to 10 years later. Ranma is back in Japan. And, sensing that, Rachel sets out to find her life-mate...