Hi Nick,

For your questions:

1. You can, we prefer to create same report but separated views for browser and export ( as we do in our example). So the exported report can be different a little with the view of report on browser. May be in the exported pdf, you only want to include some part of report only, you can do so.
2. You can include those information in the view that used for export.
3. The data is from the report then it will be fill into the view, then the whole things will be exported.
4. In the browser's view of report, you may not need to show legend for donut chart since you can use mouse to hover but in the exported PDF, there is no hover mouse so you need to turn on the legend to show legend all the time. You do it inside the separated view for export.

Please let us know if I have not answered correctly your concern.