looks good. i have never seem to be albe to keep that species of urchin longer than about 2 years. once they get to about 4 inches in diameter they just die. after about the 3rd one (all hitchhikers) i assumed it was their normal life cycle.
those oysters are fun. be carefull some of them like to borrow into the LR. be carefull in the fact that they will squirt you when you remove the LR to rearrange.

they seem to last a good long time in the aquarium.
i like the
Florida aquacultured rock also. if i had lived closer or made trips closer to Tampa my whole tank would be done in it.
G~