The first thing I would say is that the only person who can properly interpret your dreams is yourself. The best technique I find for interpreting my dreams is "free-association" and it involves taking each part of your dream in turn and analyzing it, asking yourself questions about it such as "What does this part/thing remind me of?", "Why did this bit bother me?", "Why did this appear in the dream in the particular way it did?" etc.
You'd be amazed at how far such a technique can take you but I would add that the important thing is to be honest with yourself as it is your own subconscious that is sending you the message within the dream. However, you may uncover things about yourself that you'd rather not "hear" but the only way to overcome them is to confront them.
As far as the content of the dreams you mentioned I would say (and please don't think I'm some kind of dream expert because I'm not) that in general dreams tend to be symbolic and so people in your dreams are very likely to be parts of your own personality that may be conflicting with each other and killing people (and it's amazing how common this kind of dream is) tends to mean, again only in my non-professional opinion, a part of your personality that you want to "kill" or shrug off.
Your first two dreams seem to be similar in nature i.e. feelings of betrayal ("Bastard!") - perhaps one part of you has done something that another part of you does not approve of - and guilt (you being killed) - a part of you feeling guilty for bringing attention to it - but these are only surmises on my part and may not be at all relevant.
That's about as far as I can go. Best of luck with it.