The world need more indepth how-tos. =) Is it okay with you if we import your how-to into our wiki? We will obviously link to your/original site with proper credits given.
One problem I see is the line "LiteSpeed's Persistent FastCGI connection, which is known to have problems with Ruby, also was not tested."
The problem is not with LiteSpeed but rather with Ruby's FastCGI implementation. LiteSpeed supports persistent connections to FastCGI but Ruby's FCGI does not support this. Thus you have to disable "Persistent Connection" when using Ruby with via LiteSpeed FCGI config. This is one of the reasons LiteSpeed developed LSAPI for Ruby after conversations with developers at TextDrive which are heavy users of everything Ruby/Rails. Instead of relying on 3rd party maintainers to upgrade the Ruby's FCGI module, might as well create a best of breed SAPI for LiteSpeed and Ruby minus the short-comings of Ruby FCGI.