Studio lighting has not been a good experience.
1) If you are going to limit the number of local lights there needs to be some transparency, at least tell the user at light #8 that this is the last light that can be on. If performance is an issue, return the power to the user and let them make the call to use more than 8 lights.
2) After expanding the light count, make it so that lights can be attached to a part or assembly.