Wudhu

Q: After wudhu and prayer one sees few (say 3 or 4) black minuscule grains of something (like a minuscule grain of powder or dust) under the nails, had it affect his wudhu?

Q: As nail polish nullifies wudhu, is it okay for one with onychophagia (nail biting disorder which is part of the OCD spectrum) to wear clear nail polish or bitter tasting nail polish to prevent her or himself from biting as it is damaging to the skin around the nail, cuticles, etc and puts the person at a risk of infection if they don't take steps to stop nail biting or is it still haram despite the health risk?

Q: I had a cut on my knee and it bleeds, then I put a plaster on it. When I make wudhu then do I need to make a new wudhu for all namaaz?

Q: If I get cut on my finger, which needs to be washed for wudhu, and I put a plaster on my finger can I just make masah on that plaster? And do I need to make a new wudhu for every Salaah?

Q: I have on my feet a lot of half peeled off small skin pieces (probably from little fungal infections) mostly in the form of circles. Because of this the small peeled skins borders are hanging over the skin below i.e. there are two layers of skin. Is washing normally sufficient in order to make wudhu? Also sometimes, I have the same on my hand (2 or 3 or 4 very little circles). Is just washing normally enough?

Q: After brushing my teeth with a Miswaak, my gums bleed. How or until when, do I have to complete my wudhu thereafter?

Q: I was performing salaah and during my last sajdah I felt accumulated wind about to come out i.e. I had the urge to break wind, when I sat back from sajdah that feeling was gone. Now I don't know whether the accumulated wind came out without me noticing it, or that the accumulated wind just disappeared into my body. In such case is my wudhu nullified? Can the feeling of accumulated wind just disappear (without coming out) back into the body? Or must I regard it as having come out even if I did not feel something coming out? Should I repeat the prayer and the prayer I have prayed after it?

Q: If I make wudhu and whilst I am making wudhu I break wind, do I have to start with the wudhu again, though I never had wudhu because I never completed the wudhu?