1) Ned, Catelyn and Robb explicitly die in the outline so Sansa could very well be a surviving Stark. There are mentions of Robb, Ned and Cat dying but not Sansa. Strange how you jump to Sansa must die.
2) Potentially, but we don't have enough context. For all we know, it could be that Jaime kills everyone ahead of him but Joffrey's son survives because he was switched with someone else. There are a lot of ways this could be played. The outline also doesn't say who else is ahead of him.
3) Would the child not be a Targaryen if Jon had a kid with someone else? Sounds very eugenics-like.
Anyways, the show strongly implies that Daenerys will never have children too.
Daenerys- "I will not lie with you. And I will not bear children, for you, nor anyone else. Not until the sun rises in the west and sets in the east."
Then there's Daenerys being associated with Nissa Nissa and being turned into Lightbringer as well:
"Yet when she slept that night, she dreamt the dragon dream again. Viserys was not in it this time. There was only her and the dragon. Its scales were black as night, wet and slick with blood. Her blood, Dany sensed. Its eyes were pools of molten magma, and when it opened its mouth, the flame came roaring out in a hot jet. She could hear it singing to her. She opened her arms to the fire, embraced it, let it swallow her whole, let it cleanse her and temper her and scour her clean. She could feel her flesh sear and blacken and slough away, could feel her blood boil and turn to steam, and yet there was no pain. She felt strong and new and fierce."- Daenerys III AGOT
But even if she does, that kid could very well be sacrificed. The story is replete with child sacrifice after all.
4) Sure and this is why Robert Arryn is probably gonna live through the show.
5) I don't think Arya will die either but the outline is about the POVs and who will be consistently present through all 3 volumes not who survives the story's end. I mean Bran's pretty much dead already for instance. Not to mention that GRRM has said that his outline was bs(which may or may not be true).
6) Yes, Arya could hook up with someone else and have kids but if her future is with Gendry like a lot of people believe then it doesn't really matter. The only scenario where I can see Arya continuing the Stark line and ruling is if Sansa is bumped up to queen of Westeros or if Sansa gives the North to her so she can go rule the Riverlands or something (but that's a long shot).
7) You'd have to kill Arya and Sansa if you want Jon's kids to inherit. You don't think Arya is going to die so I don't see why Jon's kids would get the North and I don't think the show nor the books are going to jump that far forward in the future. I've thought that it could happen before but i don't see it anymore.
8) Tyrion would be the Lord of the Westerlands. I'm sure there'll be some low nobility daughters that could marry him for favors and to have such a powerful son-in-law not to mention that Tyrion could always just pop out a bastard and have the ruling King/Queen legitimize him.
9) Karstarks are Starks. And many Stark descendants have the Stark look as well. There's also people like Waymar Royce who is implied to look like Jon Snow. I don't actually think Sansa has to marry some Stark-looking dude. I'm fine with the Starks look like Tullys.
Besides, I think it's much more interesting if the Targaryens look like Starks and the Starks look like Tullys.