Why must you re-invent the wheel with this? Just use the same system as the other mmos and profit. The more time you waste coming up with solutions when the answer is staring you in the face the more people are going to get frustrated and leave thanks to the sub-par group finder experience.
Because MANY people do NOT want the same system as other MMOs. The closest I can think of that might work is Rift's system, but even it still needs to be perfected and worked out and changed to work with TOR's system.
As long as it's NOT in player hands to decide, I'm fine with it.