Writing.Com General Discussion

For the past year I've noticed my writings leaning towards the Sci-fi direction for the most part. But there are times when I write it's like I'm watching a tv show where the characters talk... a lot. I don't lose sight of the story line, direction or descriptions at all I just seem to let the characters talk. So my big question here is how much is too much talking between characters in a story? Is there a way to force myself to change this way of writing/thinking or should I just let it happen?
Also, I have this thing about my main characters getting into situations where they have nothing to lose, get their butts kicked all the time while still coming out on top, most of the time. I even kill them off to make the story, in my opinion, more realistic (actually I like killing one or more of my main characters it's fun). Are these good or bad areas to work with or get away from?