Rigid link simulation

Hi, thanks for reading!

I am trying to make a simulation that finds the equilibrium state of a network of rigid bars should some of them increase (or decrease) in length.

I've attached what I have so far. Case 1 in the file works since the network is determinate, the second doesn't work. Though my intention is for the center point to move "up" (in the z-axis) until equilibrium is found.

So...my questions are

1. Should I be using springs for this? and with Kangaroo?

2. Is altering the rest length the best way to achieve this?

3. How to get out of plane movement from a planar structure?

Thanks!

Tim