No way you can convince Drasaitl to sign for 5 million and 3 years and then trade him away!

Um you can, that's how RFA / UFA rules work. Other than an offer sheet, players basically have to take whatever they're offered until they're UFA (there is a window where they can apply for arbitration, and still get almost nothing)

His options basically are to sign an offer sheet, which EDM can match and trade him to whomever they want, OR to become a UFA that is 26 and has won a couple of Stanley Cups with McDavid.
EDM wouldn't have signed Russell at 4 million if they were going to offer Draisatl a longer term contract that would have included more expensive UFA years

You're really undervaluing Draisaitl, and I don't think its a good idea to trade him. If you have 2 amazing, 70 point plus centermen as your #1 and #2, you can make a deep run in the playoffs. Look at pitts with Crosby and Malkin.

cant trade a player for 1 year after he signs an offersheet