They will say the follow:
“We have listened to your feedback and the current state of mythic plus, and have made the following changes. We will be going back to +20 keys to open mythics to all of our player base.”
We will rejoice.
3 days later
“We have increased challengers peril to be 5 minutes per a death. We want to have serious consequences to every death, while rewarding each completion.”
Yes please
A more balanced dungeon pool would help a lot.
Just farm 4s they are very easy and you can grind to ilvl 619 really easily, the low key experience is still there and arguably even more rewarding. 
No, Blizzard will fix low shop sales first and add more store mounts.
M+ is the lowest of its priority.
farming 2s,3s, & 4s is in no way fun at all for the above average player lol
The above average player wouldn’t need to farm low keys to upgrade gear before progressing.