You could use one of the target dummy script with multiple targets and edit the rotation for the situation. Then on the report, you can just look at the DPS to the main target (there is a picker that lets you filter the results to a specific target).
No, we don’t have a way to do that - it’s not possible anymore with how complicated gear has become.
But, you can use the simulator to get an idea of what types of gear might be different from our default strategy - like more haste or whatever, and compare what BiB picks with some other sets using the simulator. If you find a trend, you can use the customize options to push the simulator towards a different stat, trinket, legendary, etc.