Two problems/questions!

Alright, first, is there any way to stop Heros from giving experience on death but allow normal units to still grant experience?

Secondly, My items with custom icons don't show the grey cooldown icon when you use an item generated spell. I think there is a problem with my paths or something.. So does anyone know exactly what path it uses for item cooldowns?

Do you have a Disabled version of your item icon imported? It should have the path "ReplaceableTextures/CommandButtonsDisabled/DISBTN<Your Icon Name>".

If you're talking about the Cooldown specifically, it shouldn't need a seperate Icon.

Yep and it doesn't show the grey overlay when I use the item ability.

No, I'm not talking about the cooldown specificly, I'm talking about the grey animation after you use an item that goes on cooldown. Like if you use a potion, it will then have the grey overlay that shows that its on cooldown..

Are u referring to the small almost clock like overlay that happens when you use, say a potion? If so could it not be a game constraint thats disabled.

does the spell /item in question have a cooldown?

Regarding question one, you'll need a custom EXP system I believe (I just so happen to have made one :D). Maybe there's an option for it in the gameplay constants, but an exp system would be easier.
Here it is if you're interested: My EXP system