About your Characters
Your character, X, may it be a main or alternate, dies at the hand of Y.
Is is NOT acceptable to have your main, another alt, your next character, or any of your characters for that matter, seek justice or revenge in any way against Y. Sometimes it will make sense IG to go after Y but it cannot be because he killed X. This is blatant metagaming.
Avoid any stories that connect to your past characters otherwise it leaves room for OOC and metagaming and a lot of headaches for many people. If someone talks to you ICly about how your former character died, try to steer the conversation away and perhaps even give a friendly tell to your fellow players: "Hey, X was my former PC, can we avoid talking about him too much? I don't want to end up metagaming anything. Thanks."
I know it is unavoidable at times, especially if your last PC was famous. But you have to keep in mind that your current character knows nothing AT ALL about your former character and has no link with it whatsoever. All you might learn randomly is that Y killed X. Your current character does not know why, how, where, when, nothing. So lets just avoid metagaming this as best possible people, it will make things easier for us and you. Goins after Y may be IC and very tempting, but as a fellow DM said "It may be IC but not being lame OOC is important and can usually be justified IC somehow. Even if it's deus ex machina style with a "my leg hurts"."