What are the primary goals of creating a building model? Who are the key stakeholders?
The primary goals of creating a building model is to display a potential 3D model and rendering to the clients that have commissioned the work, so they can picture how the final result will looks and whether or not the building that has been created actually suites their needs. In this model you are creating a Field Research Station, so most likely the key stakeholders would be the researchers or the company that they work for who has commissioned a building to be made to suit they current and future needs.
How much detail should you include in your building model? How do you decide?
As you develop your initial design, I believe that there should be very little detail. During this stage of the modeling process you want to make sure your building meets all of the main requirements while containing the most important features that were asked from the client. As you continue to iterate and develop your design the intricacy of the model and the detail should increase. You should be focusing less on the key features that you established in the first step of the modeling process, and instead be focusing on how the smaller details around those key feature come into play. Each stage should be more detailed that the last by including more parameters and features than the last.
Many door and window manufacturers provide Revit families for doors and windows that you can specify for your building design.
The advantage of manufacturers providing Revit families for doors and windows that are able to be specified to your design is that they can continue to market their products without actually having to display the physical model. My including the option of having their doors and windows in renderings and models it allows for consumers to see their products in context of buildings and begin thinking of using them once the building is realized. As a designer it is a lot more beneficial to use these manufacturer-provided families, because it allows for uniformity within models of different kinds without them having to be identical. It also allows for the client to picture a fully furnished version of the building you are modeling which adds to the appeals as well as entices them to imagine their own furniture. Finally, you are able to save time creating new window and door families by using the ones provided by manufacturers, while typically eliminating any personal error that may go into their design or having to search for the perfect family within the Revit library.