We're going back to WDW when I'm 14 or 15, and I want to ride Rock 'N' Roller Coaster. I have a few questions:Will my head hit the seat when we launch? Will I pass out? Will I have that feeling in my guts at all?

Not if you hold your head back. I really doubt you would pass out, my 11yo girls rode it with no problems. It pulls close to 5g in the first loop (more than astronauts experience during launch) so you will feel the G's I doubt it makes you sick or anything, it may be in of the fastest rollercosters on Disney property but it's tame compared to others out there.

Don't worry about these things. Listen to WhatsApp Jared wrote and have Fun! I and my 14 yo son where very nervous and woried in the line before the ride and after the ride we wanted to go again and again! Be Brave! You Love It!