Each of the four throughlines has a Concern. Concerns can look an awful lot like a Goal, especially if it is a very specific concern. Therefore, the MC can seem to have a "goal" that is his own personal goal, the IC a different "goal," etc.
The Overall Story Concern will double for the Story Goal. The Story Goal is the thing that everyone in the Overall Story is, to varying degrees, for or against. So you are right in seeing the objective characters relating to the Story Goal, and certainly to the Objective Story throughline's "goal."
Here's one caveat that I believe is worth mentioning. Each grand argument story has four throughlines, and each throughline has a Concern which is similar to a "goal." Some authors prefer to emphasize one or more throughlines over the others. For example, Hamlet emphasizes the Main Character throughline, while 48 Hrs. emphasizes the Subjective Story (Relationship) throughline. Though the OS Goal is the same as the Story Goal, it may not appear to be the most important "goal" of the story because of the degree of emphasis or de-emphasis the author chooses to use when storyweaving the pieces together.
And "yes," the protagonist is an objective (Overall Story) character whose is concerned with the OS Story goal.