Balancing Attack Range and Movement Speed
I have noticed a general problem that affects just about every champion in League of Legends. That problem revolves around attack range and movement speed. I am going to list 10 champions' statistics involving these 2 things.
650 attack range; 325 movement speed
175 attack range; 325 movement speed
125 attack range; 335 movement speed
550 attack range; 340 movement speed
175 attack range; 340 movement speed
450 attack range; 335 movement speed
125 attack range; 350 movement speed
175 attack range; 325 movement speed
525 attack range; 340 movement speed
175 attack range; 340 movement speed
Do you see the problem? While it's not always the case, there are many ranged champions that are faster than melee champions. Now, these numbers have a pretty small difference when it comes to movement speed, but the gap enlarges when you consider how not only are most movement speed items percent increases, but there are also more movement speed items for ranged champions than melee champions. This makes a gap that keeps getting bigger and bigger until a melee champion has around 380 movement speed and a ranged champion has around 420 movement speed.
So, it's pretty obvious that the higher one's attack range is, the lower the movement speed should be, but what numbers should they be? I have worked out a series of numbers I think would be balanced. Another note, I think it is an unwise idea to go above 600 attack range as you would be able to use Rapidfire Cannon to attack a turret without ever getting attacked back.
AR: | 125 | 145 | 165 | 185 | 205 | 225 | 245 | 265 | 285 | 305 | 325 | 345 | 365 | 385 | 405 | 425 | 445 | 465 | 485 | 505 | 525 | 545 | 565 | 585 MS:| 375 | 370 | 365 | 360 | 355 | 350 | 345 | 340 | 335 | 330 | 325 | 320 | 315 | 310 | 305 | 300 | 295 | 290 | 285 | 280 | 275 | 270 | 265 | 260
With the changes to these numbers, it would not be necessary, but would increase the potency to also adjust the number of movement speed items that are meant for melee champions versus ranged champions.

With this update, it would cause another problem. Turrets simply don't pose enough of a threat to ward off divers. Some updates to turrets would need implemented. These are changes to 3 statistics I would implement. (Important note: ordinarily, the damage and armor and magic resistance increase over time, but I don't see any need for it as time brings turrets.)
Turret: | Outer | Inner | Inhibitor | Nexus Damage: | 200 | 225 | 275 | 325 Health: | 3800 | 3600 | 3300 | 3000 A/MR: | 60 | 60 | 60 | 60