I understand that Gauss' Law (or manual integration) yields that the net force inside a hollow, uniform spherical shell is zero at all points.
However, for a spherical shell with finite mass inside of it, we say that it pulls the shell inwards on all sides equally. By Newton's third law, this should imply that there is an outward force being applied on the object that is inside as well.
But how will a spherical non-rigid body at the centre change its shape with time due to an equal amount of force being applied from all sides? Say, if I kept a semi-solid object at the centre, would it stretch all the way till the walls and stick to it? What if it was off-centre? [Edit: People seem to not realise what I'm asking. I know the net force is zero, but that doesn't mean that there are no forces to begin with. A non-rigid body changes its shape when anti-parallel, equal forces are applied on it.]
Will a rigid body at the centre not feel pressure from being pulled from all sides? In stars and planetary bodies approximated as uniform spheres, while calculating pressure at an arbitrary radius inside the sphere, why do we consider only the forces inside the elemental shell under consideration?
(For question, see Irodov 1.216 pg45: https://imgur.com/pMCiWqW ; this question is not directly relevant to my query, but it's what incited it)