Layering the hair

Q: Can women keep their hair 2 lengths? They call it layering. According to what I heard from one Aalim is that Nabi (s.a.w) prohibited from qaz (shaving the sides and keeping the hair big on the top), but to have a small difference is ok. For example to cut 4 on the top and 3 at the bottom. So my 2nd question is that is the fatwa that we generally learn from our ulema regarding males is on a precautionary/taqwa basis?

Eating lungs

Q: Would it be permissible to eat lungs (kalaiji) of any halal animal? (Actually one of my friends is baralvi he told me that it is makrooh e tehrimi and should not be eaten)

Euthanasia for dogs

Q: An elderly couple inherited two dogs from their son, due to some family situation. The couple are unable to maintain the dogs, such as feed them and take them out for the daily walk. By nature, this particular breed of dogs are considered very dangerous and aggressive. The couple have been unable to sell them or give them away, even to the SPCA. In this particular situation, is it permissible for a vet to euthanise (put down) the dogs. 

Covering the Satr...

Q: I was told that covering up satr at all times is farz e daimi. Please let me know the ruling when 1.) alone 2.) in front of spouse 3.) in front of other mahrams. Also what will be ruling for women for the same question. If I’m alone in my own house where there is no risk of any non mahrams entering, can I wear clothes that slightly show my satr like shorts or when my pants are below button will I be sinful?