[lcstorc]

Looks good.
You need to slow down until the amonia goes back to 0. With each addition you are likely to get a small spike and it is important that you let the bacteria keep up with new additions.
If you keep the sponge you need to clean it frequently to avoid becoming a detrius trap and nitrate factory. Twice a week is the frequency I hear most. I removed mine entirely and never ran into a problem.
There is no reason why you can't have light over the rubble it just doesn't need the light. The cheato will need light so if you have both you will want a light.