so basically i'm going to disagree. I'll start with the last part First which would be the stuff about his W; The thing with his W is that he can use his E right after so the thing is, often when you W in there are only a few champs that can consistently punish you and prevent you from E'ing out.
As for range and poke, this is a big no; see the problem is you are looking at him like he is some sort of enchanter and it appears from what you are saying that you want to be able to trade with him..This is wrong..Rakan is just Like Alistar/Leona in their philosophy except Rakan's trip isn't 1 way, These are all in Champs, they aren't trying to trade with anyone, they want to get their CC off and kill the other ppl, not poke poke poke then all in like a mage. If they make him more like an Enchanter well then he would be able to do too much when he already does a fair amount, so it would be a scenario where you just give him more tools and more ways to kill when his playstyle was suppose to be all-in but if you buff Q dmg or range (without nerfing anything else) now you are giving him the ability to also trade with poke poke poke and then all in without any way of stopping since he already poked you down, basically he just 1 v 2'd..
I think you maybe misplaying Rakan based on what you are saying which basically has nothing to do with his Kit or the other supports but more about you.
If Rakan needs anything I would say maybe a buff to his shield.
I would say what you seem to want is Zyra if I'm frank. You want to be able to control the engages but also want to be able to harass in lane.
Play Zyra and stop playing Rakan
