yes, it has both job oriented results and academic too. though it is a skill based science but you can use your prior knowledge of ENVS to make innovative things out of it.

Yes. It would be a good combination of education. GIS has many applications in both economic and environmental science

Yes, and I encourage you, but the scope of your work remains, is it at the core of GIS work or is it distant? For example, if your studies are in the purely theoretical field, I think working in GIS does not serve you, but the opposite is in the field field and analyzing samples, or let’s say all specializations.