The closest I've gotten to something like this were my Blogspot and Tumblr Blogs, where each one was a specific character of mine, as if they had gotten a blog and just started writing. However, all that remained intact was their species (two of them are anthropomorphic rabbits and one of them was an anthro fennec - a fox with big ears) and their personalities. Razzle, the fennec, did arcade games and is supposed to be the voice you hear on my gameplay videos on YouTube, Tamagi would do various music-related things, and Niko uh...he kinda just...I never actuallly found something to do with him. I imagined him being a blog for writing but I never really got down to writing stories myself, only creating characters ^_^;;
There are lots of Tumblr blogs that are in-character though. Like, fully in character and talking about and mentioning all sorts of things from whatever universe they're from. I've also thought about bringing my Blog personas on here somehow, but I'm not sure.
When I do my in-character posts, all I do really is just get into the mindset of my character and just let it rip. What you're planning sounds kinda interesting if done right. Not sure if it's the kinda thing allowed on HP, but I suppose time will tell.