Parametric planting

Hi there,

I'm Landscape Architecture student and new to grasshopper.

I have been assigned the task to generate a planting plan/configuration through the use of grasshopper. I'm struggling with the following:

1. rotating a circle around the circumference of another. I have achieved this with the circlex3tan tool, but can't figure out an alternative method.

2. Lets say three circles are rotated at once and each circle possesses a point on its circumference, is there a tool that forces the points on the circle to repel away from each other on rotation forcing the points to never achieve their closest distance away from each other. 

Great, I hope that this question is clear.

Thanks