When someone comes back to life, it's generally unlikely that their alignment will change. Evil players will hardly ever become neutral or innocent. Innocents, and to a lesser extent (generally due to their smaller numbers, I guess) can come back as evil players if a team has a 'rezconvert', in such that resurrecting someone makes them join their team. Some players have auto-rezzes, nearly always OMTs, too, where they'll automatically come back after dying.
When roles are kept hidden after a player dies, this could really mean one of two things, in my books. Firstly is that the player has an heir and is much more likely. Often you'll end up executing a baddie, only for everyone to sigh as their role isn't revealed, implying there is now an heir out there. Heirs are very annoying - sometimes they lose their old roles, but sometimes they keep their powers. This can make proving your role an ineffective way of clearing yourself. Secondly, it could be that an auto-rez will trigger. I only really thought of this because it happened the other day in another game I'm playing.
If I were to initiate in role trading with a player, I'd generally ask them for their role and expect them to tell me first - I think this is a pretty fair demand, though I can be a bit of a pushover and be coerced into going first. The way I look at it is that if you ask to role trade, you're probably an innocent, as baddies don't want to go flaunting fake roles as someone may expose a loophole. If their role seems legitimate, I'd reply back with my role. Sometimes I might forget to send a role back if someone asks me to role trade - generally it's a good idea to have a fake role ready, if you're evil, and be ready to reply. Being reluctant to role trade will definitely set alarm bells ringing. A bandwagon may form on you to 'pressure' you, or you might be dreamt (and subsequently shown as evil).
I'm not sure I totally understand the second bit of your last post - but if someone doesn't reply to your role trade, it could either be because your role is flimsy and they wouldn't want to give their role in return, for fear of being killed, or they're evil and haven't coined a fake role. Obviously whichever depends on the circumstances. Things to avoid when creating fake roles - percentage based powers, claiming plain innocent, claiming things like... selfish healer, where it's very hard to prove that your role does that, claiming coroner, claiming tracker. Many of those will set alarm bells ringing, again, and you could find yourself up for execution.
Some people choose not to role trade, and of course that's their choice, but can be their undoing in a way, too, if they're evil, being high priority dream targets if known for their stubbornness (for how else are you going to get information about them?).
At least, that's what I'd say, on those things. XD
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