My complaint is that you're using a definition of Otaku that assumes that the movie "Dragon Inn" falls under anime for purposes of what the fandom covers.Otaku had got a pejorative sense in the past, but now it is not alway like this. At least otaku lacks of pejorative sense in Spanish community who love manga and anime.
There isn't really an overall term for "fantasy manga" - particularly since there are a whole bunch of sub-categories - like "isekai" anime and manga which are portal fantasies where characters from our world are whisked to a fantasy world (usually after getting hit by a truck or getting trapped in an MMO, but not always). However, often those fantasy worlds are explicitly based on Dragon Quest - which is in turn heavily inspired by Ultima and Wizardry, which take their cues from D&D.
There are still fantasy works set in feudal Japan in various periods (the Shogunate like with Blade of the Immortal, the Warring States period like with Inuyasha, the Heian period like the Onmyoji films), but there isn't really a particular catch-all term for those works - oh, and you also have fantasy works set in periods that are inspired by feudal Japan but don't entirely fit (Shin Megami Tensei IV, the Utawarerumono series),
Xena and Hercules aren't Wuxia. They're a sort of modern campy sword and sandal series. Wuxia has some specific cultural tones to it - and I don't just mean "oh, it's Chinese, is in live-action, and has special effects", I also mean how the community of martial artists and warriors are depicted within the setting.* I remember the series Xena: the warrior princess and Hercules: the Legendary Journies with some pieces of "wuxia".