Purdah

Q: I am 52 years old. I wear a hijab but not a nikab. An Alima advised me that this is fine as long as my neck & chest is covered. Please advise if this is true or am committing a sin by not wearing a nikab?

Q: 

1. Husband picks up wife at work. As she gets in they both kiss one another. Is this acceptable?
2. In a working environment, in a meeting comprising of various sects what is the common etiquette that a Muslim women should display, defend her point of view loudly, be argumentative, etc.
3. What does Islam say about women approaching men, say in the lifts, coffee breaks.  No intention of any kind, just trying to be friendly and courteous. Seeing a fellow worker, and saying "Paul”, how are you, how’s the work etc. Sometimes he may just walk past, but you greet him, hey Pat, what’s this. You as a female make the first approach.
4. The trend of holding hands in public especially married couples.

Q: A person went for Hajj. He doesn`t want to speak to his Ghair-Mahrams on the phone after coming back from Haj. Is it correct what he is doing?