I think the idea of (F2P )minigames is very interesting to bring new players to EXODE. If they like it, they will see what else you can do in EXODE. That being said, i think there will have to be enough content (in the main game )to keep them entertained or they might lose interest very quickly.
I like the 'space soccer' idea a lot to, in my head it has a 'blood bowl' vibe, smashing and brawling your way to the goal. While the other team might be very agile or fast depending on your faction.
Another idea for a minigame could be; you control the alien ships and have to make sure nobody escapes from a space station. Playing this game should also teach you how to evacuate more succesfully.
Actually, I almost did put "playing aliens and finding player planets" as a 4th minigame proposal :D I just thought it would make players feel bad to be detected.
Organizing mass attacks in the pre-evacuation with a preset of fleets could be viable too, reading reports and committing fleets.
Or as you say, making sure no one escapes from a station!
But here I am stopped, because I like to keep the aliens and their fleet profile as a mystery that players should investigate.
As for the space soccer, I am glad you see the BB vibe in that because that sure is a good reference.
Nice idea on the evac mini game, it would give a good intro to the game.
But I think a functionnal colonization loop is needed to keep players, you're right. Otherwise they might get bored.