1, 3, 4 - Those are pretty standard dungeon symbols: https://dysonlogos.blog/2013/12/23/the-key-to-all-this-madness/.
2 - If you uncheck Rotate-to-fit, north will always be up.
5, 6 - It's not an adventure, it's just a map. You can start wherever it makes sense to you. Like on most maps numbers mean nothing here, I could replace them with letters. Choose Notes mode > Tailed if they bother you.