I don't think it matters where the Spurs play, they can win anywhere, much like the Mavs, the Suns on the otherhand do need home court as much as possible because they are not battle tested.
I think the Mavs are a lock, I think only the Suns can upset them. With the Spurs they've seen that done that and they are better this year than they were last, the Spurs don't seem to have improved apart from TD being healthy. I don't think any team can really challange the Mavs other than the Suns, it is quite possible to play their style of b-ball all through the Western conference, ala the 1987 Lakers, it wasn't until they faced the Celts in the finals that someone was able to force the Lakers to play half court b-ball. Suns could follow the same pattern but IMO the Mavs should be too much this year.