I'd like to suggest that running wordpress with buddypress may fit the bill... and if you need chat (instead of the chat-similar groups messaging which is baked

I'd like to suggest that running wordpress with buddypress may fit the bill... and if you need chat (instead of the chat-similar groups messaging which is baked in) - you can also add wisechat to the mix. This system is loads easier than matrix imho - although I love love love matrix and want it to continue to succeed and be used. Blocking spam user signups and setting security plugins and auto-updates is not baked in.. but it's not hard and it's all open source - can run on a droplet or vps easily.