What type of Mandarins? Mandarin gobies? They don't do well in captivity. Mandarin gobies need a constant source of live food and if they don't receive that they die. The mandarin goby is not a good choice for an aquarium. Basically the same thing with the raccoon face. You need to get "reef" fish, like tangs, clowns, angles, etc. Snowflake eels are nice looking but will usually get sucked in or find their way into your pumps (where they perish) so they are also a poor choice.
Your questions are far too general for me to provide a definitive answer.
You don't say how you went about setting up the tank or providing me any history of the tank, such as how much liverock do you have? Did you cycle it before you added fish?
Do you know about cycling liverock?
I suggest either purchasing my book , or if your looking for free beginner information on cycling etc.. read my several FAQS As far as gluing down your anemone... Im sure that would stress it to death. They have to be able to move around as needed. They do this for lighting needs and food.