hm, I am not sure. Till now I could not find a bookmark functionality in Emby, but it normally remembers the last position I played the file. If this is what you meant with “resume point”, I guess it would help a lot to have this, yes.
I do not really know what “chapters” are. But as most audiobooks have their tracks, chapters might play a less important role.
Displaying multi-cd content could be importent, but maybe this already works out of box. And being able to download audiobooks for offline use would be awesome.
Else I do not know any further specialties dedicated to audio books