@i0n0s: You can't respawn in SP, so it isn't an issue.
When a player respawns, he definitely keeps all event handlers applied to a previous incarnation via addEventHandler (he obviously still has any hard-coded event handlers applied in config too). The init isn't run again though, but XEH 1.8 intruduced a "run init again on respawn" flag. Not sure about respawning vehicles, but only because I've never tried it.