Well I don't think it's as bad as you're making it sound
A deviation of +-20 points isn't harming anybody and would only be temporary for 10 games that they play, the points others gain and lose wouldn't even be affected I don't think. I can see your concerns though which is fair enough.
My idea for the random matchmaking (IMO) is one of the best, however I don't know if there are enough players for his to work fluidly. This would also have to be implemented in another lobby though or as an optional thing as the "Laissez Faire" would go nuts.
Ah, you go and tell to Voobly players that "a deviation of +-20 points isn't harming anybody", and see what happens

That`s why the concern.
But you did mention a range of 1550-1650, which is 100 points (+/- 50), and not to say that once a player has more than <certain amount> of games (which masking would award him), and his rating is above 1650 (which masking would award him), that player is pretty much above the average (not because of the points, but because of the Voobly competitiveness, drowning beginners to below 1500), and if someone decides to play such a player he has some expectations of a certain game-play level - which he won`t get because he`s been deceived.
I don`t want to make it look worse than it is, but it is bad. It would help beginners for sure, but it would ruin the experience for others.
Through the years of rated play, the "main" lobby has reached a certain level of skill, and that is why people refer to Voobly as to more pro-game environment. If we want to include beginners into all of this, let us not ruin the fun for those that are already playing on Voobly, but prepare the beginners before (and if) they join the experts.
Exactly as
dfs explained earlier - if you already have a Champions League, but you would like to include more teams, then don`t ruin what you have just in order to make it easier for others - no, make a separate league for the others to expand their skills, and when (and if) they reach a certain level (of confidence, or some pre-set goal) they will enjoy the Champions League as everyone else is enjoying at the moment, not ruining the fun for anyone.
Also, aren`t there like different "Leagues" in StarCraft II, too? I`m not much into it, but I think they have a certain league gradation system, where as you advance you join the higher (more skilled) league. We don`t need something as advanced as that (though it is nice), but an organized, separate lobby for beginners sounds like a good starting point.
Just think of ways to make it even more beginner friendly (suggested automatic match making, designated "hosting players" to help others, good advertising, etc). As I already said, the biggest issue would be how to populate this new lobby in the beginning, not to be empty and boring, later it will grow on its own. I guess the best solution would be to have some kind of "volunteers" to sit there and help newcomers. Yes, no one is going to pay you for that, but you`ll have the satisfaction of knowing that you actually helped someone, and they won`t forget it. There`s not much else beside that in the community work after all, but I guess that`s why it usually involves a special kind of people
