Faraaidh and Sunnats of ghusal

Q:

1. For ghusal there is the condition of washing your whole body. I want to ask that if one is in the shower or using a bucket to take ghusal, is it necessaray that every time new drops reach the other part. I mean that if I am taking a bath under a shower and washing my head or chest then the water flows from my head to my chest or legs and my legs get wet automatically. So is it necessary for me to wash my legs again?

2. Is it necessary to remove any impurity before taking ghusal? I mean, if I wash the najasah from my body, does that part need to be washed again for the purpose of ghusal?

Q: I suffered from continuous bleeding for many months now it's not continuous. But when I calculated my period time and break I calculated wrong. What should I do now? Mistakenly I considered nine days for period instead of ten days. I do wudu before ghusl everyday but I didn't have any intention of fard ghusl after completing 10 days. Are all my prayers fasts in ramadan unaccepted? What do I do now?

Q: I am in a big problem. I'm really afraid of wet dreams. Last night I saw a dream. It was not of sexual nature, just a lovable nature but I feel as if I was aroused. When I woke up I felt wetness but it was the same wetness I felt a day before when I was awake (I'm thinking it's regular vaginal discharge). I am unmarried so I don't know what mani looks like. Is ghusl still wajib on me? Please suggest because I have doubts in everything, even in wudu prayer and other things etc etc.

Q: I have 2 questions on Ghusl

1. Is gargling obligatory in ghusl or passing water inside the mouth is sufficient for ghusl to be valid?

2. Is sniffing water inside the nose obligatory in ghusl? I have heard that "Istinshaaq" i.e. taking the water into the nose and breathing it in to the end of the soft bone is required for ghusl to be valid.

Q: For a female not to have to wash the entire hair does it have to be plaited from before she enters the state of janaabat or can it be plaited in the state of janaabat before making ghusal?

Q: Will it suffice for a woman whose hair is plaited to wash the roots of the hair or it is necessary to wash all the hairs?

Q: Wanted to ask, recently had keyhole surgery and was in haidh but now need to take a bath to become clean. Because of stitches been told not to get that part of the knee wet. Would running across wet palms across that area suffice for ghusal?

Q: Tap water that comes in my house is not clean. So when I perform ghusal, I don't gargle. Instead, after doing ghusal I gargle with clean water. Is my ghusal valid?

Q: If a mango string is stuck in my teeth, I did my best to clean my teeth before making ghusl mindful that all mango strings are taken out, after ghusl I read salaah and quraan. The next morning I ate thereafter I cleaned my teeth again and I found a small single mango string from my teeth. Is the ghusl, salaah and reading of quraan valid? The mango string is as thin as hair.