Most Helpful Girls
Absolutely not, unless the person is a family member, relative, or childhood old friend whom he does not have feelings for other than brother and sister type of relationship, but that's for "hun." I don't know and can't think of whom can be called "babe" besides significant other, or a partner.
Not unless its a sister or a best friend they've known for more than 20 years or somebody extremely unattractive and poor.
Most Helpful Guys
If it's a regular part of her vernacular, I'm not worried about it. But if she uses it sparingly and with men in particular, and with those whom she speaks to regularly or flirtatiously, I'll probably get jealous and bring it up.