Here are some of my replays:
5v5 pro game May 2010
1v1v1 (This might be for regular, Vanilla Sins)
Hard fought 4v4 on Diplomacy
HuyMac gets Outsmarted
Long 4v4 on Diplomacy
Ultimately, you'll just have to dive into online multiplayer at some point and accept that you're going to get thumped as a new player while you learn the game. Experience is a good teacher when it comes to Sins. Focus on trying to stay alive and on being as big of a pain in the ass as possible. Then you can watch replays of all your games and look at what the good players did.