In my opinion the best thing you can do is get the Framing and Mosaic Wizard add-on for SGP. It’s so easy to use, you get the exact visual framing you want, the exact angle you want and the wizard fills in the plate solve coordinates for you. This will address your questions about framing an object.
Unfortunately I do not have a rotator so I can’t help there. But if you have “on target start, rotate to:” enabled then the software should move the rotator to whatever angle you tell it to. So if you’re having an issue with your rotator I’m guessing that this is a problem, and not just a misunderstanding of the software.
Please see this post on how to ask for help: