The problem I see is how are you going to use the Cable Company's coaxial cable? I'm pretty sure that's illegal.
I get the point that you basically want to setup a LAN within your town amongst a few houses, but I doubt you can use the coaxial lines to do it. If by some chance you can, to run a standard IP network over coaxial you'd need some enterprise/ISP equipment I'd think. You still don't exactly have a way to output it though.
You also can't exactly run Ethernet between houses either without some kind of approval from the city I'd think. Unless you do it at night
I think the only way your going to get by the laws and what not is to setup a Wi-Fi network. If you have a direct line of sight between houses then you could achieve nice Wi-Fi signal strength. About the only way I can see your plan working.