I've tried out some bounce-settings in the past:
If you need only shadows or AO 1 bounce is enough
For reflections of metals, mirrors or other reflective surfaces you need at least 2 or more             bounces, for simple reflections 2 is enough, but for more complex ones, like two opposing mirrors you need more.
For refraction you need at least 3 bounces, I've tried to render filled glasses with 2 bounces but the fluid inside turns into a black ink.

When you use point lights, you have indeed no other option than to use Ray-tracing, because for depthmap-shadows you need a specified direction of the light and pointlights shine in every direction.

-How can you improve things when you don't make mistakes?