I want to touch on option #1 as you have it listed. The primary problems with the solo queuing option are as follows:
1- At the beginning of a season, everyone starts with the same rating and thus putting you in a situation no different than queueing solo for normal groups. So, you're just as likely to be grouped with people in recruit gear that keyboard turn and don't keybind abilities as you are someone that is awesome. Only, one or two super bads can crush your team where as one or two awesome can't take it to the promised land.
2- Solo queues already put your team at a disadvantage because you're not guaranteed to have a healer or tank present. Why would anyone want to play a rated game without any healers?
3- Solo queues also don't help with team variation. I've landed in games where I was one of 5 or 6 Snipers (my alt). I've also played games against 5-6 Marauders/Sentinels or 5-6 Pyro PTs/Vangards. Now, of those three offerings, which one do you think did worse?
4- Finally, coordination will be utter garbage with solo queues just as it is now. People want to win and it is much easier playing with friends/teammates that you know that you can depend upon to do their jobs and have a means with which to communicate when needed.
The ONLY way that solo queues would work is if they tied in the same system that is currently on the LFG tool. When you queue, you list what role you play and then the game groups accordingly with 2 tanks, 2 healers, and 4 dps. You're still not guaranteed to be grouped with bads and you'll lose out on coordination but that would prevent #2 and #3 from happening.
Ultimately, I think what needs to happen is the implementation of a 4man group queue for rateds. In WoW, 5 man arenas were damned near impossible to get going because getting 5 people together at any one time was absolutely brutal let alone trying to find competition to play against. Rated BGs was just as bad and that required 15 people to work. Right now, the game doesn't have enough population to really support a healthy 8v8 match (unless they add in cross server competition) and people that want to do rateds can't because finding another 7 competent people is kind of difficult.
Yes and no, because you're going to be getting grouped with people of similar ratings, after enough games the good players will float to the top and the bad players will continue to squaler where they belong. For long seasons ( like what I expect will be happening such as the case with preseason) this will create the seperation of people so everyone gets a somewhat competitive match based on their ratings. Bad people will not continue to get carried up to infect the higher ranks. It just takes a long time, but trust me it will be worth it once everyone is geared.