You can't change imagepoints or hotspots at runtime, however the s plugin has math expressions that are the equivalent of imagepoint rotations, called get offset something or other
You basically put in the x and y offsets, and the original sprite coordinates and angle, and it tells you the x and y coordinate it would be at rotated at that position.
If you're going to be resizing there is a little more math.
Let me know and ill try to get an answer if my job ever let's me leave