OK I have just 4 simple things to add to the game
1. Make a guild menu that can be hidden.
So instead of going/guildinvite blablabla you could target them and press invite guild then their could go into the guild menue where you could c hoos on rite there and just click the name to pm them.
2. Make a buddy like like that (mabee even the same menue with a tab on top(you could also do this with a party)
3. Make a bank to store your stuff in
4.Make monsteres drop Crystals (or money stuff)