That the installer just installs their version x in their path, with a working shortcut etc., and not care if there are other versions installed or not. I think other games like Battle for Wesnoth do it like that. Of course I'm assuming that this restrictive behavior is just legacy and can be disposed of.

What do you propose? What would you remove or what would you add?

Joining the lobby should be possible from anywhere, unless your country blocks it. Joining someone's match on the other end is another matter. The only solution would be dedicated servers you can join, and that requires money.

It should though... Mods should install next to public if thats passed.

P.S. I am aware of the option ' pyrogenesis.exe -writableRoot"     to store runtime game data in root data directory, but this is not it in full.