A lot of things have been added and improved, but I'm sure there's a few things that still need to be worked out. Once we have a few people using the club functionality and live sessions to display we can see if there's any major functionality that still needs to be addressed.
Right now there is no way to send messages or chat within rcflights.club directly. That is intentional. This tool is meant for managing clubs, scheduling events and accessing live sessions. Talking in-game would still be the way to go if you need to talk to club members.