Impurities on the body

Q:

1. Once after urinating some drops came and I touched it with my hand which was less than a dirham. At that time I assumed it to be water and ignored but now I think it was urine and with this same hand I touched the water bottle and I didn't wash it. Since then when I fill the bottle with cool water the outer portion also gets wet and my hand too, so was my hand najis all the time and I might have touched other objects after the hands got wet. I also might have prayed salaah in this way. Will my salah be valid? At that time the impurity was less than a dirham, but due to filling the water as the outer portion also gets wet, will the impurity spread and exceed the size of a dirham and make me najis as well?

2. I get a lot of waswasas about purity and about many other things. Please tell some effective ways to fight these waswasas. I try to ignore but I fail.

Q: What is the diffrence between mani and mazi?

Q:

1. If my lips bleed and I lick my blood and then my lips are clean and there is no trace of blood on the tongue, are my lips and the tongue paak.

2. Due to sweat and scratching dirt remains in my nails and I made wudu and I read salaah and then after sometime I noticed dirt in my nails and I am not sure whether it was before wudu or after wudu. Is my salaah valid? Is this kind of dirt permeable.

Q:

1. While brushing my teeth my gums bleed and when I try to wash my mouth by rinsing in the basin there are splashes of water back on me. Are these splashes napak?

2. When there is a nose bleeding and while washing there are splashes back on me are they napak?

Q: When wiping an area that is napak, does the water that drips from that area become paak?

Q: I was praying and I realized I had mucus on my hand and the mucus was there before the wudhu. What do I have to do? Repeat the Salaah?

Q: We shower in a tub. When we take a shower, water collects at one end of the tub though the tub has a drain but the water collects at one place and we use our feet to push that water towards the drain. My family members sometimes don't push the water and use the towel to wipe their feet and then place the towel with mine. Will my towel become impure? Sometimes the water seems soapy.

Q: In medical school you have to take anatomy class and dissect cadavers (dead-bodies) of non-Muslims and maybe Muslims (I am not sure if there are any Muslims that donate their body after they die so I think all the cadavers are non-Muslims).

1) Do you have to do ghusl after dissecting?

2) Do you have to do wudhu after dissecting?

3) How many times do you have to wash your hands?

4) If you touch the clothes you dissected in after you do wudhu or wash your hands do your hands or things the clothes touches like your bag become napaak?

5) Does the rulings for questions 1-4 change weather the dead-body is of a Muslim or non-Muslim?

Q: I have been struggling with OCD and trying to get better and not take so long when doing wudhu but I keep having doubts which makes me take like 15-20 minutes for it. As a female you get discharge and the area is always wet and has a white mucus. Every time I go to do wudhu I think I have to clean all of it off but its' always there next time because it is naturally supposed to be there. So I spend so much time washing over and over again and scratching to take it all off because I think only poring water on the area doesn't clean everything because it sticks to the area 1) Is it sufficient to just wash the area with water by pouring it over 2) Do you have to scratch every little bit off? It is very time consuming and can cause pain and infections because I keep trying to remove something that is naturally there.

Q: Is the sweat and saliva of a person who is in a habit of eating pig paak?