It takes time for coral to grow. That said, even when it is happening it can sometimes go totally unnoticed. I've had small frags, like my orange monti, feel like it is never growing but looking back on other pictures it obviously is.
When it comes to how much light is too much, I'm not familiar with your lighting. I can however use the fact that I have my Radions set at 60% and are 10-12 inches off the water. I can keep SPS
almost in the sandbed.