Packing circles of different radii within a boundary surface/curve

Hi,

I'm pretty new to both Grasshopper and especially Kangaroo, so please be gentle :-)

I'm stuck with two problems with Kangaroo that I'm not sure how to solve best:

1. How do I pack circles _inside_ a surface (or curve, whichever is better) (so that it's not just the center point, but the entire circle that stays inside)?

2. How do I make sure that the circles of different radii do not overlap? (my current use of SphereCollide doesn't seem to be working)

I hope the attached files will give you an impression of the issues I'm dealing with.

In advance, thanks a lot! (and if the people behind Kangaroo see this, thanks for a great plugin, super-excited to work with it!)

Best Regards,

Kevin