Unable to create a profile of spanning tree

I have seven physical DC’s each corresponding o a physical office, with seven subnets and seven AD sites. After looking into sites IP links I found out that the previous administrator had one link to a site named northwest and in it was all the sites. This made KCC generated some issues, being unable to create a profile of spanning tree. All the sites are efficiently connected by a business ADSL [5/50mbps] or cable and links to a VPN. First of all, is Northwest some kind of default name? And secondly is it advisable I make a site link from each web site to every other site and maybe create some kind of mesh network? Or maybe use a hub/spoke with the Head Office in the center where the FSMO roles are situated? Help me out please.