What is the ruling on buying, selling and eating sturgeon?

Is it a sin to look at the photo of a painting which depicts an imaginary woman in nude?

Recently a documentary showed chicken runs in Pakistan where blood, veins of animals and meat of animals not slaughtered according to sharia are given as food to chicken. It made people worry as to what is the ruling on consuming such chicken? Is it permissible or not?

Some stores sell frozen fish. Is it permissible to buy and eat such fish?

What is the ruling on looking at a non-mahram woman?

Is consuming white alcohol, which is advised by physicians for heart problems, permissible?