You can adjust this problem of players flooding after connecting, if it is one by adjusting these settings in q2admin.txt to a higher setting...
These are server admin settings. Not something a user can do.
It is generally a bad idea to make servers more tolerant of userinfo changes. Why? Because userinfo is not designed to be changed very often in the game and some features can be used to lag the server or other players. The default settings work just fine. They weed out the players who have picked up bad binds from somewhere that do things like change hand/skin/fov while firing or who change skins like chameleons.