Everything About Hirelings I've Been Afraid to Ask.

[Nobunga]

Hirelings confuse me. I understand that they have two chief abilities.

1. They can hold one item and have said item's bonus count for you.
2. They may be sacrificed to automatically escape from one monster.

I guess my questions are
Do ALL Hirelings have these abilities, even if they don't say on their cards? Or just Hirelings from certain sets?
Is there a limit on what items a Hireling may carry? (Big Items? Race and Class restricted items? Steeds and Vehicles?)