@Petros @usulrasolas @nonlinear markdown seems to be in active dev, see here:
https://github.com/tootsuite/mastodon/issues/853. I've implemented it myself on a test instance and it works but is server-specific, so the markdown will only federate to other instances that have similarly implemented it. not sure how i feel about switching to pop-up markdown editor / embedding CP if you exceed the count.. at the end of the day this is supposed to be a micro-blogging platform. i think it'd be cleaner to introduce your topic and then post a link to more info (eg, a pad, like you mention in point 3). those are my initial thoughts, at least