Webmaster tools could easily include such things as SEO tools, (inter)network tools, etc.
Freelance tools (IMO) would cater more for things like contracts, per-hour payment calculations, invoice tools, etc.

They're both very, very brief lists of what might be available but hopefully it gets my point across. Sure, a webmaster and a freelancer (whatever their career line) might use some of the same tools but there is a larger difference between the two than it seems you see. You even outline a key difference: "Freelancers develop websites, webmasters run them." That's actually a very big difference (to me).

With regards to your SEO statements. So you're going to include "web hosting" or "programming & databases", "advertising", "marketing", "legal help" in the page title's keyword list for topics/pages in the appropriate category?