Do the assassin guild quests go on and on forever or do they have a stopping point? If they go on forever (will there be anyone left alive) then why are they in my main quest line and not misc?

Radiant Quests? They go on forever.

I think every faction has Radiant Quests that go on forever.

And, you can't depopulate the gameworld, each "Mark" is generated for each Radiant Quest.

Indeed. I felt stupid, chasing down all those contracts for the DB only to discover mother will never be satisfied.

I decided I'm just going to give her a bouquet of Nightshade and call it a day.

That was the one thing I hated about the db questline.

I didn't get that at first. I thought it was a new big quest.

When I got the quest to kill a noble at Dragonsreach... and a little later got a quest to kill a noble at Dragonsreach again, and one that looked identical to the first, I thought "twins! How intriguing!" It wasn't untiI got the same quest a third time, I realized