Xfiles
No. His last appearance is in episode 22 of season 2, the last episode of the season, titled "Not Pictured". However, in the series finale, "The Bitch is Back", (the title of this last episode) you see a portrait of Duncan on the wall of the Kane's house.
Astrid is the name of the Kane's housekeeper. In the episode "My Mother the Fiend" we learn that Mrs. Kane agreed to pay for Astrid's schooling, which makes Veronica think that she is really Mrs. Kane's abandoned daughter.
Veronica figures out who killed Lilly in the last episode of season 1, which is episode 22, titled "Leave it to Beaver".
No in one episode they fake his death but no he is still alive :)
One Son 6x12
Xfiles
yes
D.D. Alvin Kersh
yesssssssssssss he is the whitest white man ever his name is Kane
Samantha Moulder
Kane
yes he has
Yes, he had.
Yes. Kane from 2012 is the same Kane that debuted in 1997 and nobody has ever played the character other than Glenn Jacobs, except for the impostor Kane storyline in 2006.
Morley
Yes, twice