What is the damage of the best Destruction spell compare to the best Bow?
Keep in mind, no enchanting or potions or poisons, just perks will be counted with.
Just compare the best single target Destruction spell with the best Bow.
I'm asking because I have no idea how much difference there is.

Will the destruction spell be dual or single cast and does DoT count in this? For archery would the "deadly aim" perk in the sneak tree be counted or would it be the highest damage out of sneak mode?

I have some idea, but I'm probably way off the mark.

Yes to all. All that would be counted.

if sneak damage is included then archery would win against all destruction spells as destruction magic recieves no benefit from sneak. When out of sneak it would be a lot closer but the impact perk would probably swing it for destruction IF the target has a weakness to that kind of magic and you had a large magicka pool as you would be able to do more damage before the enemy reaches you. Master level spells are also more powerful than archery as they can effect multiple enimies at a time (with the exception of lightning storm). However when you take into account how much the higher level spells cost in magicka, archery would be the better option unless you used enchanted items which you said did not apply. In short unless you reduce the cost of destruction spells or sacrifice health and stamina, archery is better.

A bow can do well over 2k damage while a spell can do maybe 200 damage

You can smith a bow, destruction's damage will be left in the dust.

destruction svcks in all ways.