OK my idea for a looking for group system come from not enjoy the WoW system and wanting to keep group's on the same Server. The LFG should work abit like a lobby system without being in a lobby. You put your self up on a list, This should be done with tick box's. SO for e.g. I'l would Be showed as Smuggler lvl 10, DPS, Black Talon. If i dont want to make a group then I can sit there.
Then you have a option where somone can make a group (make a game if were going back to the lobby system) That person can search through all players that have listed them selfs for groups and filter accordling. Then place everyone they picked into a lobby then once everyone it happy they click a button and bang its a group. Then you all meet up doing your question and get a high five at the end.
This would need to be its own button on the UI otherwise no one uses it lol. I think in games like league of legends or world of tanks the custom game finder systems works so well that I dont see a reason why the princables wouldnt work in a MMOLFG.
Instant locking people into a group I believe wouldnt work due to player might not want to play with x person and locks and blocks should be allowed. E.g. you can block a player from inviting you because he ninja'ed your amazing helm for his comp lol.
On a personal note I havnt had any issues finding groups I dont spam chat or in a guild. I message people asking them if they would be intrested in doing X. It works REALLY well. 90% of the time players want to do the content and I can see if there a Jugg or Power tech and ask if they can tank / heal (for healing classes) as I myself play DPS. But I dont know if players know they can talk to each other and not spam chat.