Okay, here's what I've brain stormed so far:
Ties aren't rubber bands, but more like shocks on a car.
Really good shocks anyway.
Each tie has a resting length, and a spring coefficient (for those familar with physics). When you change the length of a tie you have to pay energy based on the potential energy of a spring equation (which I don't remember at the moment. So sue me).
Changing the springiness of a tie costs some energy too. Or maybe you have to set it when you fire it.
Pretty standard so far. Nothing too new. However, as a stretched spring applies force to its connected bots, it has another force that slows it as it approaches its length.
Like this:
|\..........
|.\.........
|..\........
|...\____
----------
0....5....1
Where y axis is velocity of a connected bot and the x axis is the length of the stretched tie. Assume its natural length is about 1.
That should stop the ties from oscillating while still allowing them to stretch and apply forces to bots.
Also solves the problem of translating forces along a MB. Bots that move stretch or shrink the tie, causing the tie to create forces on both the moving bot and the connected bot, which is itself translated along the MB.
Bones would just be a tie with a inhumanly large spring coefficient.
I've gone over the math for damped oscillation once before, so I'm somwehat familiar with the math.