BTAs attach to liverock. They like to have their foot in a cave or overhang in the rock. As far as current, moderate current is fine. There is a risk of a wandering BTA getting sucked into a powerhead and destroying not only the anemone, but also releasing toxins into the tank that could kill other inhabitants. So, it's recommended to keep intakes covered with screen. You definitely have plenty of light. In fact, I would say the anemone should first be located in a lower light area of your tank (unless it had already been acclimated to similar lighting.
You mentioned that the anemone is "puffed up." It can take days to weeks for an anemone to acclimate to a new tank. During that time they can deflate and assume generally unusual positions.
As far as the feeding regimen: After the anemone is firmly attached and not moving, you can try to feed a piece of silverside about the size of a pea. Place the food near the mouth on the tentacles and keep an eye on whether it eats. Sometimes it can take days before an anemone is acclimated to the point of eating. Once it begins to eat, feeding two or three times per week is sufficient. As it gets larger you can feed the equivalent of a peanut a couple or three times a week. Larger anemones can eventually eat the equivalent of a whole silverside, but this would need to be chopped up into peanut size pieces.
BTAs need water that is in good shape regarding parameters: temp. 78-82F, specific gravity 1.025-1.027, nitrates preferably 0, ph 8.2-8.4, etc.
Good luck with your new anemone. Hopefully your perculas will take to it--but you never know how long that's going to take.
