1) You can shave or they can...I always shave myself. 🙂
2) Yes (kinda). Bring your music and earbuds. Eat. Drink. Rest up the night before. Bring snacks. Lots of sugary snacks. Six hours is a long appointment. Bring a pashima or hoodie to make yourself extra comfy. Don't forget your phone charger!
3) You are going to be stressed about your flight but you will be fine. You will be all wrapped up!
4) There will be plenty options to drink you water, coconut water, Gatorade, etc. It's not like you are pinned down.
You got this!