Tahaarat

Q: In fard ghusl under the shower is it possible for any hair to remain dry?

Q: What is the proper method of cleaning a chair (which has najasah on it), if the chair is of the same material as a sofa (i.e. the chair is not a
non-porous surface)? Is using a wet cloth sufficient to clean the chair?

Q: Do you have to gargle in fard ghusl or can you just move water around in your mouth like in wuduh?

Q: I woke up and there was this whitish liquid that was inside. It hadn't come out but after I urinated got up and everything it hurt and I am quiet constipated but I didn't go to pass stool then or anytime before so should I consider it as wadi? The only time I went for stool was yesterday evening and later yesterday I went to the toilet put pressure but nothing come out.

Q: Can we wear cotton socks inside the leather socks, and will it affect the wudhu when making masah on the leather socks?

Q: If a person did not know the fardhs of ghusl for years and would just take a shower when needed ghusl, and he may have gargled mouth and blew nose in the shower but don't know 100%, will the salaah, saum etc of all these years have to be repeated?

Q: When one washes one's hands in a wash basin/sink, or makes wudhu in a wash basin/sink, there is almost always some splash back from the sink. Is this splash back considered najas (impure)?

Q: The underwear I had on I cant like really see any round patch on it so should I just consider my body paak and consider ghusl to not be fard?

Q: If a cloth has najasat will washing it with soap suffice or we have to wash it 3 times?

Q: Okay I have a question.. and I really do need specific instructions/what to do; please do give a descriptive answer to clear my mind of any doubts.. 

[This is from what I can remember because it was a while ago] 

So the day before I believe I had a 'nocturnal emission' [wet dream] and purified myself. Then the night before I wore a pair of bottoms that I hadn't worn in a while. When I woke up I believe it was fajr time, [can't remember if I had a dream or not] entered the toilet and noticed whitish like tiny patches that were not concentrated in one spot [as it would be normally] nor was the surface of the bottoms to my knowledge 'crusty'. Also it was dry, not wet or damp.. I think the bottoms still smelt clean [Might of been washed before I wore it]. So after thinking about it to myself for a while. [I did have doubts before to do with wudoo' [waswaas etc. but rarely or never before with emissions] I changed, did wudoo' and thinking that it was stains/white specks from a while ago I prayed thinking that I was okay and not in need of wudoo'.. I did have doubts though and later, [after fajr I believe] had a shower [just a normal shower I believe] Now I really don't know and I am confused.. It I was definitely sure I needed ghusl I would repeat the salah... but I just don't know and I am worried about what to do... Please help me