Ghusal

Q: I have a question regarding ghusl. I get constant doubts about the validity of my ghusl. If someone performs ghusl and then sleeps and then does salaah at night but at night time they get a doubt that if the eye and eyebrow was properly washed in ghusl or if it was accidently left dry (note this is more based on doubt rather than certainty). The person then goes to the bathroom and washes his eye and eyebrow with the niyyah of completing the ghusl. Is this valid and he does not need have to repeat his ghusl?  If one hesitates to wash it due to waswasah or because he isn't sure, does he become napak again?

Q: I would like to find out about sleeping in a state of janaabat, is it fine to sleep in the state of janaabat with ones wife after relations? As a habit is this fine as well? There is no problem waking up for fajr. Just in terms of the consequences I would like to know.

Q: One does ghusl and goes to sleep. Then one awakes and takes wudhu and puts on his khuffs. Then his wudhu gets broken. Then one finds out that there was a solid substance in the cave of his tooth. Does he only needs to remove it and wash the place? Is his masah still valid i.e. can he take wudhu with making masah over the khuffs?

Q: 

1. A person begins fasting in the state of janaabat. Regarding ghusl in this state, is the ghusl valid if the water does not reach the inside of the throat or the inside of the nose (i.e. these actions cannot be exaggerated out of fear of the fast breaking)? Will the ghusl be valid if the water did not reach deep into these areas? Or would the person make ghusl washing the nose and mouth as in wudhu and upon breaking the fast would the person then gargle the throat and wash the inside of the nose properly?
2. A person forgets that they are fasting, and thus gargles and washes the nose intensely so that water is accidentally swallowed. Is the fast broken, bearing in mind that the person forgot that s/he was fasting?

Q: Can one recite quraanic aayats of Dua like Aayatal Kursi for protection in the state of haidh or janaabat?

Q: Is it necessary to remove surma and kaajal from the eyes when taking a ghusl?

Q: After mastrbuting is Ghusal is Wajib on boy or Girl?

Q: Is it compulsory for every muslim (male and female) to perform ghusl on Friday?

Q: I am 22 years old and work in an IT company. I have to interact with a lot of girls all the time to solve their computer issues and while talking to them I get excited and a white liquid flows from my penis. But, it does not lead to ejaculation. Altough my intentions are not pervert I had this issue when I used to carry small kids as well but it has stopped now. But I still have this issue with girls.So,does it break my gusul ? Do I have to take gusul again? Is there any way to stop this?