Time & Averages can save LoL

What I mean by that is we need to ask ourselves a couple of questions:

How long should the average game be at each elo?

How long should the average laning phase be at each elo?

How long should the average mid and late game be at each elo?

What should the average kill/death count be at each elo?

When should the average tank come online?

When should the average fighter come online?

When should the average slayer come online?

When should the average mage come online?

When should the average controller come online?

When should the average marksman come online?

We also need to consider the replacing some damage for utility meaning what can be done to reduce burst in fair exchange for being able to do something else.

Please share your thoughts.