Impurities on the body

Q: Does getting urine on one's body require that person to perform ghusl? Because in old age sometimes one gets a few droplets of urine on oneself
without knowing, what should one do in that case?

Q: A person has a rash like eczema on his scalp. Sometimes it bleeds a little. At night unconsciously he scratches it and it bleeds sometimes. Now it is very difficult to know where it bled etc, and at fajr time he simply makes wudhu as normal without washing his head. There may be some dry blood on his head. Is performing salaah in this manner permissible or does he have to wash his head completely every morning to make sure there is no blood? Sometimes for Fajr he has to be the imam of a small musallah when the Imam is not there?

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: If mazi comes out do you have to wash the kusyatain also?

Q: A person touches the private part of his wife, does his hand become napak?

Q: I wanted to ask a question regarding purity when I go to toilet for a urination. I often get up and I find some drops leaked. So now I rub my private part upwards lightly 3 times to take out excess urine. So will rubbing the private part to remove urine release semen and will I have to do ghusl?

Q: Please can you advise me with regards to whether when urine falls on my skin and I wipe my skin and ensure it is dry. If I subsequently perspire does my clothes as well as all the places I sit on (bed, chair etc) become napaak and do I have to clean these surfaces by wiping them thrice?

Q: Can we touch a dog? Does the wudu remain? What should we do in case of a dog lick?

Q: Just before salaah was started by the imaam, i gave a hand to someone. When I smelled my hand I smelt some perfume odour. The person's hand was dry, in this case if the perfume he used did contain alcohol or any other impure ingredients did they transfer to my hand? Is my Salaah valid?