Party and Solo MMR difference

So, the current ranking system among its flaws has one that can be easily fixed in my opinion, however there are a few issues that I need reddit's help to resolve, and maybe a few more that I haven't considered pointed out.
#The problem has two sides:
* People (mostly tholse with high solo MMR) don't care about party MMR and therefore [feed/grief/throw party games ]( https://www.www.reddit.com/r/DotA2/comments/3pp4tf/7k_player_kingr_and_his_friend_feeding_couriers/) and

* People that have low skill get high Party MMR by stacking with better friends
So, the obvious solution would be to limit the difference between the two to for example 200 MMR (random number, would change). That would solve both problems depending of course on how you handle accounts that are on the edge of that limit.

#The problems I could think of and would like your help to solve are:

* What happens when someone who has 4000 solo and 4200 party (given the 200 dif limit) loses a solo game? My take is that losing a solo game should also drop his party mmr by the same ammount. Generally, I don't consider it a bad idea that Solo MMR directly affects party mmr in some way since that is a "truer" indicator of skill (that would mean that being 4200 solo - 4000 party and winning a solo game would also boost your party mmr). What do you guys think about this?

* The bigger problem is what happens when you have 4200 party - 4000 solo and you win a party game (or 4000party - 4200solo and you lose a party game)? I only see two ways with this, either block ranked party matchmaking until you qualify (difference<200) which I don't really like but I would understand if implemented or have party mmr affect solo mmr which is highly abusable. Both solutions are crap, so, any suggestions?


P.S. Of course other things need to be done, like better report screening and punishment (although I am not a fan of allowing "bad things" and then punishing for them, I'm pro prevention) or hero mmr, or other things but this is much easier to implement when the problems have been resolved.