Earlier quoted context omitted.
Is this sarcasm? I don't mean any disrespect or negativity, I just don't understand. I'm not familiar with this space, but I don't see why the aforementioned expectations are unrealistic. The only issue I can imagine is big media companies strong arming a player in this space (which I assume is what happens to existing companies mentioned). There's nothing technically impossible mentioned.
Ebooks, photos and emulators? In my opinion they don't belong in my cinema app.
I don't know the use case where being able to read eBooks from the television is desirable. It certainly doesn't meet my definition of shared entertainment, which is something that media centers are intended for. They're media, yes, and they can be organized, sure--but is there a common use case for reading from the large screen? Unless one is disabled, I really don't see one.
However if looking for a better merge of Kodi and gameplaying I cannot recommend Batocera enough. It has a large retrocomputing (emulation) capability and also supports many DOS games and Windows games via dosbox or wine and has recently added Steam integration. On the media side of things it can be configured to automatically load kodi and seamlessly transition from Kodi to the Emulation Station frontend.
There will be some configuration but once configured it has in my experience generally stayed configured well and can be a set and forget type of appliance if you take the time to organize your games and media and then leave it alone after scraping. Also it's been one of the easiest configurations I've done in a long time. I encourage everyone to look into it.