INFJ. I like how he side steps the question when asked why some people "need to put something in their body that alters them" (drugs) by simply shifting perspective instead of answering the question directly:
JF: "Every second alters you. Every single thing you've ever seen alters you. Everything you eat alters you."
Interviewer: "Okay, but that's an extreme form of alteration."
JF: "I don't think so. I think a parent yelling at you is an extreme way to alter you."
Strikes me as very INFJ.
(Also, when he's in poor appearance like this, does he look like a young Johnny Greenwood a little bit?)
If you could be anything you want, I bet you'd be disappointed--am I right?