John,
I would agree there is not much to be seen here, but during the off season and after the morning train leaves there is not much going on in the yard. Of course, in the morning before it leaves and evening after it arrives, there is car switching that can be seen at this location. And the north area location would have the advantage of watching the engines coal, sand, water and drop ash, which is an attraction in itself.
Maybe what should be considered for Area 9 is a viewing platform accessed from Terrace Avenue and adjacent to it. Maybe it could be a linear platform with a shelter and benches, a park-like atmosphere elevated but not overly intrusive, to let the visitor see the morning/pm action at that end of the yard.
From what I see so far, I like the commercial area south of the restrooms as it will give a museum/visitor center room to stretch. As far as parking goes, it isn't that far from the station. One downside for the business community is that people visiting could block spaces for commercial businesses on Terrace Ave. I can see that this could be a problem in getting community support for that location (ignoring financial considerations), so parking will have to be addressed there. i don't see as many businesses north of Fosters, though I'm sure some will open up if the RVC is sited in the north area.
More random thought comments after the next set of pictures go up.