I just "discovered" the tool myself and played with it a bit. (Using CC HTML Editor v12.8 build 691)
Really useful tool! Right now, I'm just using the tool to Benchmark a site.
Like the OP, the first thing I noticed was that the spider dialog prevents any further use of the Editor. I guess I can work around this by launching another instance of the Editor, but it would be nice not to have to do this.
Had no issues exporting to CSV.
Wishlist:
1) It would be nice if the spider could save and import/reload the scan results. For my site, it processed some 17,000 files and it takes quite a bit of time to process all of those pages. It would be very useful if I could save and reload the scan data into the spider.
2) Right now it seems external links are ignored. It would be nice if the spider would report the server status of the external links. (i.e. 404 or 200) That way I can easily see if any of the external links referenced by my site are "broken".
3) The opened Spider tool should not prevent the subsequent use of the Editor instance from which it was opened.
Bug:
Sometimes, the spider reports blank/empty Description and/or Keywords when there are, in fact, keywords and descriptions in the appropriate meta tags on the page.
Looking forward to using the Spider and Websight Insight for site cleanup and (hopefully

) SEO improvements.