From a non-hostile perspective...
I find it beneficial on occasion to re-evaluate how I present my character, whether its my speech, appearance, and/or my actions. I would urge other non-hostile characters to do the same.
I would highly recommend self restraint when determining appearance and equipment. I would also use caution with words and tone when talking to hostile characters. These two alone may be enough to avoid an escalation of a situation. It is important to remember that what may have only resulted in a bitching match (aka big dicking) in normal times, may result in a bullet to the head during the apocalypse.
I would also recommend not running from every possible encounter (unless you are literally on the run IC). Often times hostile/semi-hostile characters view this as suspicious. What is this person hiding? Are they on the run? They must have something valuable... etc. If you are worried about loosing a rare item, well, that's just the way it is. If you carry a rare item, I would just say be prepared to lose it.
If you are like me and feel helpless because you cannot PVP, well that's something you will have to work on (improving PVP skills) or like I did just accept it and play characters accordingly.
Next bit is a very general statement about what I look for in hostile RP and does not reflect any of my encounters thus far on the server...
For hostile characters, as a non-hostile, I just want there to be some depth to encounters. An exchange between my character and yours. Not necessarily required or always viable but, I like to have some understanding behind an encounter. Did you rob me because I had something you wanted or needed? Did you hold me up because you are looking for something or someone? Are you trying to bring order across SZ? It doesn't really matter. Just something to help progress or create a story between our characters.