1./ you go to the “Surfaces” panel in Daz Studio, and adjust the “Reflection strength” setting / value.
2./ It allows Daz Studio to import and export in Poser formats such as CR2, PZ2 etc.
If you click on any Plug-in on the list , it’ll show you a brief explanation of what that plugin does.
EG: Poser importers :
Provides the ability to import Poser format assets (pz3, pz2, cr2, lt2, cm2, pp2, fc2, hd2, hr2 - and their compressed counterparts). Additionally provides the ability import the ascii Wavefront Object (.obj) format.
Hope it helps