Incidentally, on the rendering time -- it appears you are making use of reflection and refraction as well as ray traced lights.

The best way to speed up the rendering in such a case (for example, when doing test renders) is to change the lights to non raytraced, or, even better, simnply turn off raytracing in the preview.

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)