re Q2: I'm a long way from being convinced that a series of links to similar sites (i.e. those offering your kind of service but in other geographical areas) does anything at all for you (and even less if the links are reciprocal ones). For instance, why would someone with a toothache say in Torquay possibly have any interest in someone in Manchester who could fix the problem? Real estate people do this sort of thing all the time and I think their effort is totally wasted.
If you want to improve your web presence and/or
PR, the answer lies in better and additional content. In the field of denstistry, for example, how about "Why do teeth ache?" "What you can do you to make your teeth last longer / look whiter / etc., etc."
In other words, build your site for the increasing benefit of its visitors. That, I'm absolutely sure, is what the search engines want to see and that's what they'll move you up the SERP line for.
Duncan