2 things.
1) its not just luck, its also poor finishing. Liverpool are incredibly wasteful. Especially Suarez, his shots to goal ratio since he joined is pretty dire. Its like something from FM, you have the quantity in the shots but not the quality.
2) re the tackle, yes wins the ball cleanly, but his follow through is two footed, off the ground. it is reckless and uncontrolled, and it certainly had some momentum, just ask Dembele. Very easy to see why he was given a red. It isnt just about taking the ball.
1) Last sentence..
2) It's never a red card, end of.