They're not set in stone and we really would like input from the community before we suggest what we think. We are not modeling if after any one other social media site. In general, people for the most part, I think, can move between social media sites without considering "now, what do the rules of this site say?". It's not even a thought to them.
When you said you'd prefer not to have rules like FB and TWTR, it would be great if you kind of summed up what that actually means to you. For example, I shy away from some social media communities when the discussion is a bombardment of political comments which are often fringe or extreme.