1. Maybe the preview panel would be good? It looks less "technical" and does not render the YAML header.
2. Yes, Google Drive should sync things automatically like you said
3. There's a Dendron extension (we call them "pods") that allows you to import markdown, json, etc. Here's the documentation in our wiki: https://wiki.dendron.so/notes/3e519113-5820-4a84-bef8-85103a7b296b/ Once it's imported you can just initialize the folder as a Dendron workspace and use it like normal.
4. That's interesting, what are the problems you're experiencing with Discord that Discourse better addresses?