Concealing the faults of a person

Q: I have been forced in making a kassam to something which someone confided in me! It is something un-Islamic which I think the person's parents should know about! Recently the persons parents asked me if I knew what this person was up to and I just acted like I don't really know anything. After I have made a kassam is it allowed for me to tell the persons parents?

Zakaat on jewellery, loans and outstanding debts

Q:

1. Is zakaat mandatory on the jewellery given by the in laws at the time of nikaah, which is with me after my divorce? My ex husband told me that he will pay my meher and take that jewellery back but it's almost one and half year. Should I give zakaat of that as I am giving zakaat of my other things?

2. Is zakaat mandatory on my saved money, of last 6-8 months?

3. Is zakaat to be given on my money which was given to my ex husband as a loan, but now as we got divorced, there is less chances of repay?

4. What about the meher which is also not paid?

Hanging a photo of the Kabah on the front wall of the musjid

Q: In our Masjid someone has placed a hanging painting/photo of Kaba and Gumbade Khazra at the wall near the (Member- place where Imam leads the Salah). Is it permissible to put it there. I have reservations. So far I am concerned as it diverts the attention of cautious and creative people and therefore not good to keep these things in Masjid. Is it correct?

Purdah from non-mahrams

Q:

1. I would like to know who is regarded as your mahram and who do you keep pardah from? Are milk brothers and sisters classified as mahrams? What happens if the lady who fed both of them pass away?

2. Is my step brother (both from my mother and father) classified as a mahram for my daughter?

3. Can a woman travel without a Mahram and what is the sin for doing this?

4. What is the sin for talking or even touching a non-mahram?