The renderer is a native DX9 renderer.  It's essentially the viewport.  It offers soft shadows, gel lights, subsurface scattering, displacement mapping, etc, though I'm not sure what the resolution tops out at or if it is dependant on your GPU.  There is also the Lightworks renderer built in.  V-Ray is optional.  Or, maybe I have that backward again.  Some users were initially having problems with the new way the plug-ins are packaged, but the renderer hasn't been taken out or disabled to my knowledge.  I think if you look closely though you may be surprised at some of the available images which are just screengrabs of the viewport.  And no, it's not just all of the shiny ones either...

Realtime cloth is cloth that updates with the object as you work without needing to be "simmed".  In fact, there is discussion about how to "capture" its movement as its natural tendency is to react dynamically always.  I'm not sure what the relative performance of it is.  The realtime nature may mean lower polys meshes are more desirable, though I'd expect more complex cloth objects to simply update at lower FPS.  In TS, dynamic and keyframed animated properties can influence each other.  So realtime cloth is presumably affected by environmental wind and gravity, as well as any other physical or keyed objects.