Torque is given by PESin ø, where ø is angle between field E and dipole moment P so if angle ø is zero or 180 degree only then torque will be zero while net force will be zero always because both charges will experience equal and opposite force .

opposite as both charges have opposite nature.

same force because same electric field in the region and same magnitude of charge as F=qE; so both q and E to be looked for analysis.

Note- Uniform electric field means same direction and magnitude at any point in the region of uniform field.