I have built my LMCE network "inside" my Windows network. I did this for two reasons, I sometimes use my computer for work and I need internet access to do that, and my wife really hates it when things don't "just work". So, I left my network intact and built the LMCE as a test. I had a few hurdles to overcome but I got it working. LMCE is the DHCP for it's internal network. It is only running one MD. The only issue I have at this point is that my NAS is connected to my Windows network and not the LMCE internal network so LMCE doesn't see it. Actually, I do access it from the Kubuntu desktop. I wanted to test the system for stability. Once I got past the hurdles, of setting it up, it has been pretty stable. I'm going to let it run for about a month or so and then I will put it is as my router for everything. I may manually set the IP addresses on my Windows network (using 192.168.80.**) in the range that LMCE would put them anyway so if the LMCE box goes down for some reason, I can easily replace it with a Linksys router and not have to remap shared drives and print servers. But that would be the only "hack".
So, to Anne, there may be some hurdles to overcome in the installtion process because of the particular hardware you are using. But this is a reliable enough system to run your entire network. Set up a test system within your existing system and test, test, test. Once you are convinced that it will do what you want to do, then let it do it's job. I did it and I'm not a computer professional nor am I a Linux expert.