Hi,
Your title fooled a bunch of us. I wrongly assumed you were looking for info on diving in the Maldives. I didn't look at the forum name.
You picked up a bunch of great info from the guys. Here's my 2 cents;
#1 Get closer
#2 This is taken shooting down on the moray which is always tough and looks over exposed about 3/4 of a stop to my eye. If you lower the exposure and frame for thirds you have a shot more like this;

#3 Get closer, Nemo shots are tough because there are so many. would have been fun to play with the light coming from the right to balance the light on the anemone.
#4 Nice shot, get closer
#5 Closer with a better background would be an improvement. Some of us look for great negative space and wait for fish to swim into it. I love the pair. It always amazes me how much most interesting multiple critters are compared to singles.
#6 Cool fish, get closer
#7 Get closer and compose for thirds. The bottom right 2/3 rds of this might be a cool shot.
#8 Better, would have been fun the experiment with this by moving the light over to the right a little. The anemone is over exposed by a stop and the composition puts her right in the middle. Try a tighter shot to get rid of the dead space and drop the exposure to center the light more on the fish.

#9 See that red coral/rock with the starfish behind the octo? Would have been fun to try to shoot him face on, up close, with the color behind filling the frame and the little starfish for added interest.
I hope your not discouraged by all the advise. We've all been there and have lots of shots like these. Let me try another way for you think about it. Most of us swim along and look for subjects to capture. The best photographers (I'm not in this class) look for images to make. They see the whole frame and multiple possibilities before they even move in for the shot.
Have fun,
Steve