Yesterday or Saturday while I was playing core play, Everytime a player left or joined everyone in the game had a little lag. Much like you get with custom games. Then today I was playing ranked Slayer and the other person on my fireteam and I both got kicked from the server. I checked waypoint and it looks like the other 2 players also got kicked off. Add this to the problem of one member of our fireteam not loading into the game, and getting a random instead and it is getting very frustrating. Are others having issues? Is there something going on that is stressing the servers? I know when they have the free weekends I have problems.
I can’t comment on the other issues, but I think it’s normal for there to be a slight amount of lag when a player leaves or joins. It doesn’t last for long though. I don’t know the technical term, but I think it’s because the server is “compensating” for the new set of players. The other issues you mentioned could very well have been because of the free play weekend.