Welcome to the forums. You've certainly picked a good username here! Caring feels like an understatement with the effort and thought that you've put into in packing this bag. He sounds very lucky to have you.
I do have a few thoughts, although I can't speak from experience -
Please be mindful that some inpatient clinics/rooms are strict with what they allow in rooms for safety reasons. This can be things like laces in shoes, or a beard trimmer for example. Each clinic is different so it's worthwhile checking with them or making a list of what you've packed so they can take something out if need be.
Other things I've thought that you can bring: a blanket (especially if it's cold/plus homely), snacks, so many pens (or pencils/crayons), a notebook/journal (even if he doesn't journal sometimes it can be handy to write things down).
Potentially you can look at entertainment devices, such as a tablet, ipod, portable dvd player, kindle - uploading things to use (the internet may be terrible) and chargers as well. Also headphones. Specifically listing these because sometimes phones aren't allowed on wards, so these can be good substitutes.
Finally, I really want to share and remind you that given that he's not well, he may not have the mental capacity to use what you've given him. I know that some people in hospitals do struggle to shower, so the idea of beard washes and shampoos can seem quite overwhelming, or people may wear the same clothes everyday. The reason that I'm sharing this is because potentially with your perfect packing, things may not get used and that's okay.
I hope this helps, like Grandy said if you were to miss anything or if there's something he needs, you can bring it on your visit - a lot of nurses and assistances can organise things as well. Feel free to keep in touch and let us know how you are both going.