2 things I want to do, but dont know how

I’m not even sure if these 2 things are possible with blender, but I still wanted to ask.

1.) Is there a way to create a stretchy rubber-like effect with a mesh? What I mean is if you started to pull one vertice, it would create a stretchy effect that would pull the other neighboring vertices with it and it would be like pulling a sheet of rubber. The only thing is that the other neighboring vertices would have a less intense pull, and the ones further into the mesh past those would have an even less intense pull than the ones before it, and so on. So it would create a rubbery effect. Is there any way to do that? Sorry for trying to put that into words, sounds weird huh?

2.) Is there any possible way to make an object expand in size and decrease in size when a condition is met? Example: If you have an arm that you made and its rigged to an armature, when the forearm bends at the joint it makes the bicep on the arm expand so it moves and acts like a real arm. I guess that would be deformation of some sort. But how could I make it happen when a condition is met like I explained above? Like a forearm bending?

I really do appreciate any help or advice. Thanks.

For this, you’ll probably want to use hooks.

For this you’ll want to use IPO drivers to drive Shape keys.