I hope point 1 is temporary since it might actually slow down the onboarding of new users. Especially for people who are new to Lightning - which is most of the world population.
I'm a big big fan of point 4.
One thing we don't do yet with regard to spam that we plan to do: posting the same link repeatedly within week/month.
This is a great idea. Let me mention additionally link-shortener services/websites to that.