Impurities on clothing and furniture

Q: The other day I went to the bathroom to use the toilet and noticed a brown spot on the inside of my underwear. I am not sure how this had come as I had only passed stool the night before only, and after passing stool I had went for a shower/ghusl. In the afternoon around asr time whilst in the bathroom I noticed a brown mark on my underwear and found a mark only on the inside of the underwear. My pants was black so I could not see if there was a mark, I did check and found nothing. I had also checked the same spot on the outside of the underwear and it didn't look like any brown mark there but because it was material there was a slight smell. I had sat on many places during the day, some of these places were my car, rooms in an office, doctors office, home etc. Do these places become napaak wherever I sat? I am always very very careful with regards to istinja and as said I am not sure how this happen. It might have happened when I broke wind etc. Please advise urgently?

Q: We have dawlance 5200 washing machine and it has the facility of washing as well as swill (khanggalna). It has the system of swill is like that we place all the clothes (having water of surf) in the bucket like structure and open a supply of water. The water continuously falls on the upper side of the bucket filled with clothes and get away from the downward side. After switch on the button the bucket spins and the whole process is for the ten minutes. The number of clothes filled in bucket is approximately ten. One day mistakenly my mother mistakenly wash a dirty (napaak) clothes of having mani with the other clothes in the washing machine and the swill as usually. Will all the clothes be na paak?  We have to clean all the clothes? 

Q: After intercourse with ones spouse, is it necessary to wash all the bedding and linen? Or just the spot that's messed? Also after one performs ghusl , semen comes out, is it necessary to repeat ghusl?

Q: I wanted to find out if precum is napaak? Do I have to change my underwear everytime I get precum?

Q: When I went to the bathroom I felt a splash of water or urine on my hand, I don't remember now. I didn't see it that time. I thought I will wash there but when I stood up, my sleeves fell down and I don't know where it was. 

My question is, is my sleeve napaak in both cases if it was impure water or if it was urine or if I don't remember what it was?

Q: At times when I take out a garment to wear from the cupboard, I notice some substance of najaasat on it (not just the trace), what is the condition of the other garments washed together in the washing machine. Many a times I don't even know which were the other garments as it was only noticed after a few days. And if I know which were the other garments, then in this case also,what will be the ruling?

Q: If a dog touches my cloth what is the procedure for cleaning that cloth?

Q: While watching romantic scenes of movies some fluids comes out from my private part and I think it gets transferred to my clothes and bed sheets also. How should I wash these clothes to make it paak? If I cannot trace where in the bedsheet the fluid got transferred then what should I do? Do I have to wash the whole bed sheet or should I leave it? If the fluid gets dried and after sometime I sit on the bed sheet with my wet clothes, will my clothes get napaak?

Q: I have bird pet at home, it is a parakeet. When I leave him out of his cage, he makes droppings on my clothes. Are the droppings of a parakeet tahir and can one make salaah with it?

Q: 

1. My question is that after intercourse I wipe myself. If some sperm gets on my hand I wipe it with a tissue then put my qamees on. Is my qamees paak or do I have to wash my hands before touching anything.
2. If something is najis. Do you have to wash it 3 times and squeeze each time or until there is no sign of najasaat?