Looks nice. You mention this feature: "Allow to dig different sites inside domain" Does that mean it will add 2 sites, e.g. "http://www.site.com/folder" and "http://www.site.com/folder2" instead of truncating the subdirectory?
And a request: a method of spidering faster by running multiple spiders (without conflicts) from the admin panel, maybe using the exec() command.