Oh, I didn't take it as an insult at all. I apologize if it seemed like I did :)
There are certainly a lot of flaws with my implementation, and I definitely believe you when you say that the VR movement is not very accurate. When I run it on my phone and do a 360° turn (in real life) I end up with an offset of about 20° between the library and the real world. The offset also seems to be related to how fast I move my phone around and generally how accurate the gyroscope of my device is (I get a slightly more accurate experience on my iPad). So it wouldn't surprise me if you experienced an even larger offset on a different phone.
I dealt with the mirror by simply not including it :) Since there is no actual character for the player but only a camera floating in space it would have either ruined the illusion of you really being in the library, or I would have had to find a nice-looking model and added that in, which just seemed like too much work for a small detail (and it probably wouldn't even have looked very nice).
The reason why I didn't include the toilet and sleeping cupboard was purely because of a lack of space. There really isn't a lot of space left between the staircase and the hexagon walls and I didn't want to resize everything to make it fit.
Oh and there are 32 books per shelf.