I also think Inter will take first place. As for the second place I think it could be Benfica, but Salzburg also have the possibility to compete for that. The fact that Real Sociedad will not be able to compete in this group is a fact. That leaves three clubs that will fight for the first two places.
This can still change even if you say it as a fact, because basically all the teams in one group will compete for first place. But if the first place option is no longer available, it will push three more teams to aim for second place by giving everything they have to get there. I think the competition in Group D will also be quite fierce apart from the competition in Group F which will also look quite tense because there are also many teams that are just as good.
I don't know about all four teams. It seems to me that Real Sociedad is the weakest club in Group D. Of course, this is football and it cannot be ruled out that all clubs will be fighting to get out of the group. But I think that Sociedad will not be able to compete with the others.