¹) (League games only) when a player is sent off he should be ineligible to play in the return match. Why should a random team not involved in the game benefit from not having to face this player? If he leaves in January transfer window, the other team can select a player in his place to miss the match. Token 85th minute red cards after allowing a player to kick Erling all game would then be a genuine punishment.
²) Any red card, anywhere on the pitch - penalty. Same for 'professional' or 'taking one for the team' fouls.
³) As in rugby - dissent punished by moving the ball 10 yards closer to goal. If that means inside the area, then it's a penalty.
⁴) Shirt-pulling is a foul - punish it. At corners, convert to either a penalty or goal-kick, depending upon who fouled.
⁵) VAR line calls - if they cannot decide within 15 seconds of staring at a line on a screen, then ALWAYS either rule in favour of defence or attack and get on with it!
⁶) 2 x 30 minute halves. Clock stops at every break in play; graphic on screen if longer than, say, 10 seconds; restarts when ball is kicked/thrown.
Other than those, wouldn't change a thing! :-)