Would it be possible to have a feature that gives a player the possibility to take control of another player of the same team, if it's booted from the game.

Example:
Payer 1 and Player 2 in Team A.
Player 2 gets booted for inactivity and AI takes control of him.
A voice in the menu appear (like [TAKE CONTROL]) only visible to Player A.

Asking this because I'm noticing always more and more that people join tournaments and never play, or stop playing as soon as they realize is not an easy win.

See Help > Contact > Feedback and give the idea a vote

That sounds like an amazing idea