CS leads should feel stronger

Not surprising, difference between out farming your opponent and killing them is that you can get the behind with the second one. Kills make a bigger gold lead faster the csing does so its no figure. Small amounts of extra xp seems pointless, let's the person who gets the kill on his Lane opponent punish his opponent even more. + catchup xp.

Feel like that could break the game like for example, the meta will be so focus on champions that can farm very easily and can abuse hard as punishment for trying to take cs. It seems so frustrating for people that is facing a lane opponent that is a counter to you and he able to punish you harder with these changes making it harder for you to catch up... There are positive and negative with this idea.

It is already rewarded. Try it, stay top lane, ignore your enemy laner who goes around and makes plays and just farm. You probably won't win the game when they 5v1 you but you will notice that you are the highest level in the game. Or heck, try it in a coop vs ai game. A lot of the players there are farming kills. Ignore them and cs all game long, and observe how you still retain highest level despite a low kda.

It is something you can use, champs like Tryndamere/Jax/Nasus can become raid bosses for a few mins when they have a +3 level advantage over everyone else in the enemy team/your team. I've noticed it happen myself. I tp around to make plays, come back with some kills and assists, and somehow later, I get solo dived by the 0/0 Jax because he's 2 levels higher than me.