Seewhy, that statement in itself seems to be correct, but I seriously doubt that's all to it - you have to explain all the roles (raver, seer of visions, painter, prisoner), see the whole context as one, not just pick one part.
I'd like to think, that raver (as a verb: to talk wildly, as in delirium) seer of visions and painter is a reference to the genius mind of Syd, while prisoner could mean, that he is a prisoner to his own mind, and that would explain, why is that the last.
I agree, that piper could refer to that specific album, however, it can have many more meanings e.g. it could refer to music itself.