If a charged conducting sphere is placed in a uniform electric field , will the force on it be simply qE ? I know that the electric field lines enter a conductor perpendicularly so does this have any effect on the force's magnitude or direction ?
When a conductor is placed in an electric field (uniform for ease) a force exerted by this field acts on the charges in the sphere which pulls hem apart according to the applied field. The charges separate and creates a field until equilibrium is reached. A charge q on the sphere experiences a force $F=qE$.
The electrostatic force between two charges acts along a line joining the two charges. So in this case also, the force will be always $F=qE$. The force acts in a direction of the applied electric field. That's all.