Wordpress: move media folder
You can point www.domanin-2.com to another server. You're able to do this by editing DNS records for domanin-2.com. In this case you'll be able to read files, but if you want to write files there, you'd have to change Wordpress's source code, to allow the communication between 2 servers (e.g via CURL or FTP).
I honestly haven't dived deep into this solution, as I should jump into the adventure soon; the way CDNs are setup you can separate the web server from static files onto a different server.
This is the area I am unfamiliar with, but probably could find documentation, depending on the servers configuration. You would be connecting the two. At this point, the prereqs would be Sysop level. I may have to write documentation on this as my server configuration is a bit out of the ordinary.