Woah awesome, thank you so much for doing this! (Also wild that FEZ/FUZ wound up taking almost 40% the episode!)
Regarding your points:
- FUZ is actually designed to be 100% self-contained. While understanding certain puzzle types in FEZ will help you work through it, since many of the FUZ puzzles are closely based on puzzle types in the original, they won't directly lead you all the way to the solution. At the very least, the symbols used for puzzles are completely changed from the originals. FUZ does try to stick to FEZ-style reasoning though, so yeah people who are used to thinking in those ways may have a bit of an edge.
- It's great to hear the music hit the right notes for you guys!
If you'd be interested in seeing a (spoiler-y) deep dive into the development and puzzles of FUZ I did do a whole lengthy write-up about it: http://www.jusiv.me/blog/fuz-reflections/. It will spoil puzzle aspects of both FUZ and FEZ though, so proceed with caution!