General Discussiondo u lose mmr when u abandon and lastpick random in pick phase

you wont lose mmr if you abandon before fb and 5 min (what valve says, never tested or happened to me)

from what i remember and what happened to me , the guy who abandons when lastpick random loses mmr while others dont .

i think you do, but only the person who abandoned rest of team it doesn't count.. but not 100% sure on that

ok my bad, based on this "Early abandons do not count towards Wins or Losses in your stats. All other forms of abandons will be considered Late, and the outcome of the match will be recorded in your stats, as well as updates to your Matchmaking Rating." i thought mmr not changing but later its says: "Abandonment is treated "more severely" in ranked matches.
Any player who abandons in ranked matches will receive a Loss, regardless of the outcome of the match."

https://dota2.gamepedia.com/Stats

I had a situation happen yesterday where I never loaded in. My cousin told me the picking phase had begun I never was able to reconnect got randomed + abandon did not lose mmr.

I have lost mmr in the past when this has happened though but those times I loaded in then dced during pick phase. So I honestly dont know.

You will yes

In the past you could abandon before other people connected to the game and get only 5 min penalty.

It was super good tool, since you could actually check for smurfs in enemy team or people on red days in yours. I used to cheese a lot of mmr doing that back in the days.