Regarding your visual editor experience, be sure your Obsidian settings use both "Live Preview" and "Editing Mode", which combination makes for fantastic WYSIWYG note-taking.
You can do that (side by side), but I prefer the unified (rendered AND editable) WYSIWYG view enabled by those 2 settings in combo. Whichever line has your cursor will typically show the raw markdown as you make edits, but the document as a whole is rendered.
As for multi-user, the Relay plugin is amazing.