Preseason adn placings with a duo

Just a couple things I would like to see if someone can clear up for me:

• if I don't play in preseason but ended silver will it count me as unranked or silver if I duo for placings?
• Will if you duo with a gold or higher and play vs their ranks in placements will it still push you down a ton in placings like last season?
• lastly, if you win most of your games playing vs higher ranked people than you ended last season will it help you start closer or better than where you left off?