Potential Issues with 5 man soloqueue

This is sort of a rant on new soloqueue but I'm open to any disagreements:

1. (this is my biggest issue with it) Your elo is not only yours anymore. It's the average of your friend group so higher ranking may just mean you have better friends. I feel like this would be a huge blow to the entire ranking system... it makes sense in ranked 5s currently because that group of 5 is lumped together and it is visually apparent that "oh this guys on a great team, but he himself is only silver." If you remove the line between those two then that would-be silver player may be placed vs gold+ without much practice dealing with strangers, crutching everybody.
2. Out of hundreds of games where you personally only are 10% of the game, a 95% accuracy in matching is actually a lot of error.
3. 4 man premade means that the 1 lone player could potentially be in for a very very bad time (especially lower ranks).
4. Anybody who's played ranked 5s knows that it's an entirely different game when there are 5-man premades, I think lumping all groupings into one rank is comparing apples to oranges (this goes back to my thoughts on players who would switch back and forth between 5-man and solo).
5. Lastly, I'm not sure if they're eliminating ranked 5s teams completely or not, but if not why do we need 5 man premade solo if 5man ranked teams are a thing?

-- I've seen a lot of things talking about size-specific ranks which I think would solve 99% of the issues where there would be separate ranks for 1-man, 2-3 man, and 5 man teams (4 would get shafted on the deal but let's be honest, 4 man groups already have massive potential for trouble)... sort of like a starcraft esq ranking --