So I read most of this and OP, you mentioned something that really stuck out...at least I believe you mentioned it. That was the walking through the library being able to take notes and such. If you feel hindered by having to put a notebook down and your school has handed you a laptop and display, the iPad Air sounds perfect. Since you found the iPad Pro a bit too much, I would say the Air is the best for you. The missing piece is note taking. The Apple Pencil, while I hate to admit it, is pretty fantastic. I agree with the poster about Notability as well. I would hope for the iPad Air 3 to handle the pencil and then buying Notability and you're set. It doesn't sound like you're looking to pocket your iPad, even if you have a lab coat, and it doesn't sound like you're sold on the MB Air or MBP.
I think if I knew I'd be walking around libraries and such, the iPad Air would appeal to me most, after it got support for the pencil. Leave it to Apple to say it'll never have a stylus then provide one that is pretty rad.
I think if I knew I'd be walking around libraries and such, the iPad Air would appeal to me most, after it got support for the pencil. Leave it to Apple to say it'll never have a stylus then provide one that is pretty rad.