The title says all about the subject matter. Can a point charge stationed inside a spherical shell with non negligible thickness experience forces from other charges outside the conductor?
A conducting spherical shell around a point charge forms a Faraday Cage. This system negates all electrostatic fields around it in a phenomenon known as electrostatic shielding. The point charge is hence isolated from all other electric fields outside the shell. This is also why phones do not work inside elevators.