guthriemm,
welcome to the site. Boy, did you ask a loaded question or what? I think in your reading you might have seen the "rule of thumb" for screens versus population at around 10K people per screen. Therefore, if you have around 100K people and 14 screens currently operating then, you might be asking for trouble.
But, let's set that aside for the moment. Don't think, for a minute, that you can run a six-screen yourself and keep your job. I run a single screen myself and I work harder now then I ever did previously. IF, you had an experienced manager and staff, and you just oversaw things then, maybe you could pull something like what you're proposing off, but don't kid yourself, you will be one busy guy.
I currently show what I think you're talking about when you say "second-run". It is still, technically, first run but you would just get film later then the other guys. I currently get film in the four to ten week old category and, I think, people in my area seem to be patient enough to wait for me to get the movie (in MOST cases, that is). I'm not sure how well that would go over for you but it is probably worth some thought. What you also might consider is running what they call an "art-house", which is running films that are in more limited release and are a little different then the mainstream product that the big chains are playing. There are several people on the board who run that kind of movie-house. That way, you don't have to worry about running head-to-head with the multiplexes for film.
In any case, good luck with your project and keep reading.