Salem

Do you lose this on death even if it's in your pouch?

If you die then you lose everything. Inventory, purse, money, kin list, you name it.

If you mean KO then no, you don't lose it. Even if it's lying in your inventory

Okay. How about anything that's equipped? Like a backpack

Backpack will stay, as everything else that's equipped. But backpack's contents will be dropped

Also keep in mind that a PK can KO you and take anything in your inventory and equipment slots if they have theft.