Yes. In fact they have sharp PL bands that are found superposed on the PL of the matrix. The level scheme follows the corresponding inert atom structure.

Not all metal ions. But some do show. 

If you are doing the experiment in solution and If you are getting a sharp peak in the PL spectrum then there can be other reasons also such as 

1. Raman Scattering

2. Second order scattering from diffraction grating

Metals have shining properties when light fall on the surface. where as metal nano particles case, when the light fall on, there is plasmons (ionized exciton) are created near its surface and it generates near field or evanescent waves - this also reason for kind of optical properties, evanescent wave propagate  few nanometer that is measured by "skin depth" or tunneling.

where as PL is optical transition between the well defined bands(CB, VB), usually semi-conductor materials(QDs), transition-metal compounds (phosphors), rare earth compounds have that discrete bands.

unfortunately all the materials absorbs light including metal but PL is exist only for material have definite band gap. band gap allow the relaxation process and radiative recombination to emit a visible photon.