Range Runes

No, you already have CD, damage, magic damage, health regen, sheild, armour, health, and etc. Why ranged? so you can be annoying in lane with more range? no just get damage runes.

Should this be a thing?

Towers having fixed range makes it pretty much impossible. At least for AA range.

Ability range could possibly be a thing, but it's worth noting range already scales pretty hard into late-game just due to 5v5 fights valuing range considerably more than pretty much any other quality, where defense and mobility tend to become less useful when teams group up into a ball of death.

It would really screw up the animation for melee champs.