Modern network project

hi
i was just thinking about how to connect all the stuff in a network to create a somewhat modern network... which also includes fibre-optics, layer3 switches, wifi adapters, a proxy server(cache) and voip phones....

picture - HERE

so some questions arised...
1) does the proxy server even work for all the subnets and where to connect it? -.-

2) how does the fibre-optics cable connect between the 2 switches?

3) is there any good programs to write down all the port parameters etc.. and perhaps someone could write down couple of examples? -.-

i was also thinking of giving the voip subnet only 16 addresses, use 10.0.x.x as the base address and use linux on all the host machines...
4) so perhaps it would be possible to install somekind of central managing(ldap?) server on the cache server also? to install all the necessary applications on all the hosts...

thanks