Thank you!! The answer to the first puzzle is currently the Fish rune! We're discussing approaches to better signpost this to the player right now :D
Tried it with just the Fish rune and it went perfect! Once I knew that a lot of the answers were just going to be single runes I was able to figure them all out, and I didn't have any trouble with the carving.
I'm really liking where this is headed--I like the characters a lot (the character art is so good). I'll be excited to see the whole thing!