Question about eth items...

I rarely use them, due to the fact that i can never afford to zod them, so i know very little about them. I'm wondering if you guy scan help.

Number one, if the durability on an eth item reaches zero, can you still equip it on a merc? Im guessing not .... but im not sure.

ALso, if you were to have an eth item that broke (zero/X amt of durability), can you still socket then zod it? Or is it permanently destroyed.

Thanks.