This is a very cinematic version of schizophrenia, and far more coherent and... constructive... than the usual thing. Also, more benevolent by a large margin.
Thus, you might consider avoid calling it such.
Alas, the writing is rather charming, and the character very useable in a game.
My thoughts? Call it simply madness, not by a diagnosis which it does not fit.
I thought the intro story was fantastic, it was a little inaccessable written as transcript on sound rather than a discription of sound and at time confusing, but I think that was part of its strength. For the often banal and direct world of roleplaying, most creative risks in write up of support piece such as the intro rarely play off. I think it worked in this case.
Running this character as NPC could also present quite a challenge. In roleplaying it is difficult as a PC or a GM running an NPC to play a character with a great deal of internal dialog or conflict. But the details you provide would be a great aid in trying to run such a character. Roleplaying is already surreal, we you bring in more surreal stuff into you threaten to tip the balance away from something the whole group can hold on to. But the amount of details you have the character in this post would be very help in bringing such as unhinged character into the game. the irony is that it easier to bring vague and ephemerial stuff into the game when you have the details of the vague and ephemerial stuff down pat.