Adc is the carry and as such a carry must be able to do lots of damage. One way to do that is by leveling up quicker and an ad carry can if they are solo in lane.
Mages should be supported in lane. This is due to the fact that mages use a lot of Mp to take out minions. A way to prioritize mp saving is by using a support with the mage. That way mages are free to use mp when they decide to aggro each other resulting in a 2v2 mage and support v mage and support battle.
My proposal is that we move Adcs to the middle lane and the mage / mid to the bottom lane. Thus, adc's get the exp and gold they should be able to farm for and increasing their potential for influence.