Not saying it's true, but it wouldn't surprise me if Richards had a painkiller problem. It's an unfortunate result of playing a contact sport, and when you factor in his size and style of play it's definitely plausible.
I still think they were moved because of off ice issues, just not partying or drug issues or whatever, but more likely locker room/team related issues. Their contracts were cap friendly for the type of players they were, but they were still 2 large contracts. That gave the Flyers an organizational reason to move them, but I don't believe they explore that path unless there was something else going on.
You fit other people in around your core, you don't ship them out to make room for the other people. There were other ways to clear the space that was needed for Bryzgalov's contract, and if I remember correctly Carter alone was enough to get Bryz in under the cap.