Bio wheels are not needed in any SW
tank. Infact over time they will become nitrate factores driving your nitrate readings up. Ideally SW
tanks will want nitrates below 20ppm. expecially if you have corals. An anenome is technicly not a coral but an invert so yes I would still classify you as a FOWLR
A reef ready tank is only named that because most reef tanks ustilize a sump system. Any tank with a built in overflow is classified as reef ready and they can be used in any application. FW
The sump provides NO extra filtration. All it does is add water capacity and provide a place for equipment like your heaters, skimmer, and any other form of equipment that does not have to be in the main display tank. In our cause you coudl move the biohweel down to the sump to clean up the look of the display tank.
I have an article in our articles area that really helps explain sumps and how to use them. Refuges should be seen as small tanks that are attached to your display tank system that is reserved for one or two exclusive purposes. That being growing macro algae, providing a safe place to grow copepods or amphipods, or if there is an item you MUST have for your tank thats totaly not compatible with anything else in the tank a refuge can be utlized to keep that item off by itself but still utilize the water volume of the entire system.
Having a sump does not mean you can have anything extra as far as livestock. It only adds water caacity to the system. Your still limited by the size of your display tank when it comes to stocking.