Redirect with URI rewrite setting lowercase URI and removing trailing /

How about this:

when HTTP_REQUEST {
   set sitepath [string tolower [HTTP::uri]]
   if { $sitepath ne [HTTP::uri] }{
       The lower case URI differs from HTTP::uri
       i.e. the HTTP::uri contains upper case characters
      HTTP::redirect $sitepath
   } elseif {[HTTP::uri] starts_with "/" }  {
        HTTP::uri "/site/path$sitepath"
   }
   if { [HTTP::uri] ends_with "/" } {
      HTTP::uri [string trimright [HTTP::uri] "/"]
   }
}