g1smd - 6:40 pm on Aug 13, 2011 (gmt 0)
Are your "connection refused" and "network unreachable" errors mostly on August 4th? I suddenly see a number of those on a site previously without problems.
There have been a number of occasions reported here in the past where Google could not reach a site and it was later found that the bottleneck was somewhere at Google's end.
404 (Not found) - It is concerning that URLs returning 410 and 301 are reported as returning 404. I don't know why Google does this.
Connection refused - Not sure if this is 403, or some other failure at the HTTP level.
The rest of your designations seem to be pretty much spot on.