Are pet loot packages worth getting?

If you want to cheap out on buying a pet there's always the Blackheart pet that you can get from Hilla. Although it could take a while to get one of the boxes to spit one out for you.

What's the chance of getting a box from Hilla or even the pet?

If the drops are close, the pet will loot them. You don't need to stop attacking for that, if that's what you meant to ask.

Dam! If I'm trying to fight monsters continuously then that's hard to keep up with it then