It has not been revealed in the Naruto manga or anime if Madara Uchiha dies.
No, Madara does not fight Sasuke.
How will Madara die is ALL up to the writers of the storyline on manga or anime.
No, Madara does not die.... at all. Madara (aka Tobi) is immortal, so therefore he does not die. ;)
The author never revealed if Madara Uchiha married anyone.
No never
Tobi does not die in fact he is madara
No, he doesn't die in the invasion of Konoha.
YES!that is why naruto is training to use the 9tail foxes demonic power to defeat Madara
Yes in battle against madara after betraying him.
Yes
I believe that he showed his face to Kisame