lust

Q:

1. If a woman looks at the private parts of a man without lust, does it establish hurmat-e-musaaharat?

2. A woman looks at the private part of a man in a picture or an image and feels lust, but she does not know whose private part this is. She does not know with whom she has established hurmat-e-musaaharat. Now if she is about to marry a man, should she doubt that those private parts may be of her future father in law and the groom is haram for her to marry. As she does not know with whom she has established hurmat-e-musaharat, what should she do?

Q: Is there a hadeeth prohibiting looking at beardless youth?

Q: I usually get thoughts on hurmate mushahara, like when I shake my dads hand, I am scared and worried. I don't have lust but I get thoughts that suppose it is lust. My father in law is old, about 60 something and Aalim. Now he was lying down in the room and I was in the other room. It was open so I could see who was sleeping. Now I get these thoughts about lust. So my father in law was sleeping and I went to pray namaz. I was just looking at his private parts, it was not open, he had on kafni n izhaar so I couldnt see his private part and the room was kinda dark and I was a distance away. Now I didn't have any desire but I just get these thoughts about lust. I was just looking at the private part area but father in law had on his pants. So after I saw something like a penis, I was thinking that his private part was out when he was sleeping or was it a material. I saw not sure but my heart was thinking that it was not his penis showing. I just get these thoughts and I don't want them. I have no lust feeling for my father in law and I didn't look with lust. I just looked because I wanted to see if I get these thoughts. Is my nikaah valid or will hurmate mushahara apply? 

Q: If a brother touches his real married sister with lust, does it effect it her relationship with her husband and what about the relation between brother and sister?