How does Europa Universalis 4 handle the time speed in multiplayer?
Solution 1:
Ok, I've bought the game finally, so I can answer the question myself.
From what I observed, time speed can be changed by the host, but also the players. It then changes it for everyone (note that I tried this only with 2 human players).
Anyone can pause the game. Other players can't unpause the game for the next 30 seconds.