Hello jbest,
Nice start
Good surfacing in the foreground.
I like the first lighting better, it emphasizes the surface detail.
At this point, the balancing rock looks totally unbelievable for me, although I like the idea of putting one into the scene.
I think, the image needs more different sizes if rocks.
In the distance this HUGE rock seems to b surrounded by small bebbles, while in the foreground the floor is clean between those same "pebbles".
(I prefer the fake stone shader,but surely you could use populations of rock objekts for the same effect.
I think to look "natural" you need at least three sizes of rocks, better five, your main size, two sizes up, two down. The bigger the rock, the thinner the distribution of it. In such a landscape even your ballancer could look believable.)
By the way, yes, I use the free version, and even that gives my old computer loong rendertimes.
Best regards,
Jan