Are these the right factors which contribute in MMR?

First I would like to tell a little about why I wanted to ask this question. I started Dota 2 3,4 months back as my first MOBA game. At the same time my 2,3 friends transitioned from DotA to Dota 2. They were playing DotA since it came out. Obviously they were way better than me in Dota 2 but when I learned the basics I wasn't that bad compared to them. When we got MMR (almost at the same time) I got 1k while all of them got above 3.5k. Apart from a little humiliation :), the biggest downside was I was not able to join them in party because of the difference of the MMR. Before ranked matches were open, we played in party so many times and they could rely on me both as a carry and support (with selective heroes off-course). The point is The difference between their and my game was not as large as 1k and 3.5k. So I did some research and found that there are some factors apart from wins and loses in TBD phase that decide MMR. If not all , some of them are:

1. They option you select when first time you fire up Dota2 from a new account. (I selected "Dota 2 is my first MOBA", They selected "I have played Dota 2 before")
2. KDA and SC in every match. Even before the TBD phase of MMR. (I thought I would perform good in TBD phase and I did but before that I played every solo match as practice match, experimenting)
3. The 9 or 10 matches of TBD phase have no significance except they show the last remaining matches before calculating public MMR.

There were more, but I found these three more relevant. So I have made a new account and I am trying to avoid the mistakes I made before. But I cannot authenticate the validity of these factors.
So my question is if these factors affect MMR or not?
P.S. One thing I noted while playing in new account (I selected "I have played Dota 2 before") that in my first match all the players were of 18-25 level. If unranked matchmaking also uses public or private MMR instead of player level than I guess at-least the first point is true.