Heya! Honestly a little blown away by this review - glad you're having fun with the story so far. :')
All of the music is actually Creative Commons, though most of it can't be redistributed due to licensing. We'll put up the credits list for the music in a future update. We're also planning on a "canon" appearance for MC later, too.
As for isekai recs, the team has come up with a few. Though they aren't quite the fics you're looking for, we'll likely be on the lookout for more recs in the future:
- I'm in Love with the Villainess (Anime)
- The Vision of Escaflowne (Anime)
- A Connecticut Yankee in King Arthur's Court by Mark Twain
- Princess of Mars series by Edgar Rice Burroughs