Hair and Nails

Q: I am a twenty years old. Since January I have a disease. Now I am recovering. My question is that this disease has caused my hair to turn white before age. I know that it is haraam to pluck white hair and also that one falls in Allah's eyes by doing such deeds. But I have also heard that young muslims can even dye their hair black if they wish. I want to ask that is it permissible to pluck such white hair that are growing before age and are a result of a temporary disease?

Q: I am 18 and I can't grow beard. I have only 5 or 6 hairs on my chin. So should I grow those hairs and live the sunnah or should I wait for a full beard?

Q: Are all these ways (hot wax, cold wax, razer machines, creams) to remove body hairs (legs, hands, face, underarms) permissible for a woman as there is a great misconception among people. Please do elaborate it in detail.

Q: Is it permissible for a Muslim girl to have a haircut when she wears hijab and niqaab? What are the rulings about this? I have heard a Hadith that Hazrat Aaisha (Radiyallahu Anha) used to cut her hair till it reaches her ear lobes. Is it authentic?

Q: Is growing a beard compulsory?

Q: Can a woman remove her hand and leg hairs by waxing or by razer machines or cream?

Q: I have heard that applying mehndi (hena) before eid (on the night of eid) is sunnah and will you get reward for applying it on hands and feet. Is this true according to Islam? If someone don't apply for eid or before eid, are they committing a sin? Will they get punished for it?

Q: Can a male dye his hair red or blue or any other colour besides black?

Q: In the Hadith a command is given to lengthen the beard and trim the moustache. I know that it is waajib to lengthen the beard, but what about the moustache? Is shortening the moustache also waajib? If not, then people argue and say that if you say that lengthening the beard is waajib, then trimming the moustache should also be waajib because they in the same Hadith.

Q: Can a woman hot wax/cold wax her hands and face hairs?