None of what the OP suggested would help anything. There are still far too many DPS to cater for even if everything was 8 man content (god no) or if it was one tank only you'd still have a long queue because the hundreds of DPS are all fighting each other for spots. Even with more spots per run still too many DPS to make the queue shorter.

And then you are reducing Tank and Healer spots simply to get your own way when it won't even help you. It's like this in every MMO because everyone wants to play a DPS role since big numbers = E-Peen and they are easy to level and play.