Question #1.. Is there a way i can adjust the "vanilla loot tables"?  Like add an item into what is considered the "vanilla table"?

Question#2.. Is there a way i can apply the "extra loot" only to certain containers?  So standard red/blue barrels stay vanilla, but crates, elite crate, heli crates, ect.. All pull from the Vanilla AND extra loot tables...

Thanks
James