Yes, providing they are not very huge heavy lights like Baja lights.
If you are going to replace the fender I suggest that you purchase and install the stiffener brackets as well. The purpose of the brackets is to support the fender and prevent it from breaking. Their purpose is not for attaching additional lights.
You can tell if they are there just by looking at where the reflector is positioned. If the reflector is screwed directly in to the fork through the fender the bracket is missing. The reflector is not supposed to be screwed to the fork. It is supposed to be attached aft of the fork to this bracket.
Yes, 1300. The 1100 has a similar bracket but if I remember correctly (haven't had an 1100 for a long time) the bracket that held the reflector also held the brake hoses so it would be hard for it to be missing and you not know it.