What would be very cool is to have events for when a player joins a server, with possibility to change the join text and to check if it's the first time the player joined (tho not sure if that's still in-scope), same for when a player disconnects.
For client focused events: an event for when the player joined a world/server

• Player join event
• Player disconnect event
• Client player joined event
• Player eat event
• Entity damage event for HalfOf2

Closing as some of these were implemented, and we generally track separate events in separate issues. If you want to request some events, please also provide a use case to help guide the event design.

"Entity damage event for HalfOf2" would this only get thrown if I get damaged

Connection and disconnection events are ServerPlayConnectionEvents.JOIN and ServerPlayConnectionEvents.DISCONNECT. There is also ClientPlayConnectionEvents.JOIN, although I'm guessing when you say "Client player joined event" you mean "An event that fires on the client whenever a new player joins".