AI War does not just tick off "Co-op Mode" as part of its feature list. There are several mechanisms at play specifically to enhance multilayer experience and accessibility. The two that come to mind are automatic changes in difficulty depending on the number of players (so that, for example, diff 7 is roughly the same in single player and multiplayer), and the ease of managing players, dropping and adding them as a game progresses (which allows for long games and incorporating people with hectic schedules).
Regarding the technical help you need...my advice is to take it slowly, and periodically post back here and don't give up. You certainly won't wear us out troubleshooting, but you absolutely could wear yourself out. It is probably a simple fix once we identify the issue, but it could take a while to find. The developers have demonstrated extraordinary patience working with my friends odd dual-network card setup, which caused odd problems. Also in my router, for port forwarding I can input all the settings and apply it, but unless I tick this one little checkbox the port is not actually forwarded...took me months to find that. Good luck with tech issues, just give it time and don't get frustrated.