No you cannot kill hades because he is a god but he can fade away if he is not remembered:-(
Yes
No.
The consort of Hades was Persephone.
No.
No, he did not.
Yes Hades is stronger than Zeus because Hades is the oldest brother that means he is the most experienced in combats and also because Hades is capable of summoning every human or god or anything that ever died in history that could easily kill Zeus
Not alone, no.
he killed
no.
yes it depends
Yes, Hades loved Persephone and married her.
Yes, she did.