Aside for the fact that if I'm going to join a multiplayer game I will potentially have to deal with this nonsense regardless of liking it or not, there's a problem at the source.
Multiplayer with randoms or just people you don't know is always guaranteed to ruin your game experience regardless...especially in a videogame where a lot of the players will have never played D&D even if the game was a million percent true to 5e. The best advice I have, and this would have been no different even if the game were true to 5e: play only people you know and trust and discuss this stuff with them to make sure you all agree before the game starts that nobody will touch the bad stuff.
The only major issue here is multiclassing...that multiclass system should just not exist. No multiclassing is better than this system.
