svemir

And for your first blog, you need to specify the folder name – something like:

$HTTP["host"] =~ "www.domain.net" {
url.rewrite-once = (
"^/blog/(wp-|sitemap\.xml|xmlrpc\.php).*/?" => "$0",
"^/blog/keyword/(\w+)/*$" => "/feedback/index.php?keyword=$1",
"^/blog/" => "/feedback/index.php"
)
}

The first one may continue to work, but you should probably limit it to the subdomain:

$HTTP["host"] =~ "subdomain.domain.net" {
url.rewrite-once = (...)
}