Can you remove corpses by masses via console rather than just disabling one by one? Mods are fine but I would rather not because important items may come from corpses. I want to do this to increase skills faster and yes I will be responsible if something ends up wrong with the game.

Nothing that I know of or I could find. Though I wouldn't recommend the disable command. As you will see less and less of a certain generic NPC if you keep disabling them.

I don't understand what you mean with:
"I want to level my skills faster."
"I don't want to use mods because some corpses have important items."

There is a mod to turn corpses into ash ash and some other stuff: [Clean your corpses] http://www.nexusmods.com/skyrim/mods/59340/