Why he is hated? For 0 counterplay of course. Farm safe? He will do dash dash and Stun and look at you. You are dead. Oh, I will pick champ that heals or shields me. Nevermind he heals more than me and destroys shields. Please, I am Challenger lvl 5000 and I pick Olaf, Garen or Vayne! Well wtf he killed them too.
So Renektons problem is simple and easy to fix. Nerf lane phase and make him a little bit stronger on team fights.
Get that fucking Q healing removed and make it have little bit do true damage.
W is point and click and easiest to hit. Give it tiny debuff, on Renekton. Debuff should be "Exhausted. Can not use other spells on 0.6 sec(example timing)." And if he has furry W, it is 0.8 sec(Example). You get longer stun but cannot spam spells.
E should be slower but when you level up, it will go faster. And if you dash 4-3 champs through. Your Q or W would then heal or true damage.
R is fine.