I don't disagree with 1138 that it should be the norm, and ideally it should work that way. I just had a very bad experience recently that's colored my opinion of trying to report things. I might PM you about it in a bit so you know where I'm coming from.
Back to the original topic though, I never did answer the questions from the first post, so let me see about that.
1. I think encouraging more and better roleplay from security players goes a long way towards reducing incidents of what we lovingly know as 'shitcurity'. Someone who's there to be a more fleshed out character, even minimally, is less likely to go around spewing insults and abusing fake laws. That said, they should know that roleplaying a 'bad cop' is to be frowned upon.
2. I leave this up to the officer's discretion, honestly. I would prefer they default to trying to take antags alive, but sometimes it's just not possible. One must be vigilant against defaulting to the 'it's not possible' idea all the time, though.
2a - I don't know enough about the game to answer this question.
3 - I think this is a good idea, letting them have down time, especially in code green. If we have a lot of sec staff, they could try rotating breaks? I dunno.
4 - Absolutely not. I would maintain a Zero-Tolerance policy against this.
5 - Yes. Too much strictness just stifles fun. Remember in the end that we're playing a game, not sitting down to go to work for a few hours without pay.