Ghusal

Q: I get frequent wet dreams. The problem is that it takes me about 30 mins daily to do ghusl. The main problem in ghusl is washing my feet which can take upto 20 mins because my feet has dirt inside the lines so I rub them with a pedicure stone until they are gone.

I am moving to a hostel for educational purposes and there I will have only few, maximum 5 mins for a bath as there will be a communal bathroom. Plus, the temperature can be 0°c or below too so I can't take a long bath. What do I do as I am becoming depressed due to this thing?

Q: If I have olive oil in my hair and I make wudhu/ghusl afterwards, is my wudhu/ghusl accepted?

Q: I was not able to take out one or two strands of pubic hair during shaving. I still made my ghusal for haidh. Was my ghusal valid?

Q: While making ghusl, I forgot to wash the inner part of my navel with my finger. Is the ghusl valid or do I have to repeat the ghusl? Is rubbing inside the navel necessary in ghusl?

Q: Because of my excessive masturbation, I got pre-ejaculation. If I see a girl continuously for some seconds mani comes gushing with desire automatically without even touching my private part and without me wanting mani to ejaculate. Is this because of my sickness? Most probably this is a sickness because when I defecate with force, then without desire mani comes out.

My question is:

Many times I see a girl and feel desire in my penis and I feel something is going to come out gushingly so what I do is, without holding or touching my penis I pinch myself on my legs or I think about something else so that the desire goes away and then after sometime mani comes out without any desire and also this comes without wanting to do it. Must I do ghusl for this?

Q: I was about to have a wet dream, but suddenly I woke up and saw no mazi on my clothes and nothing on my private part. After I stretched, I saw a very tiny drop on my private part. Is ghusal compulsory upon me?

Q: Can a person gargle and make istinshaaq before sehri ends and thereafter make ghusal? 

Q: Can a person face his back towards the Qiblah while bathing?

Q: If I do istinja in my shower with the water from my shower, will the floor in my shower become najis? If it becomes najis, how can I purify it?

Q: Which direction should we face while taking bath?