First off,
Your tank has a considerably high amount of hair algae (at least that's what i'm seeing in the picture provided). Most likely, the Hair Algae is the affect of having high amounts of phosphates in your aquarium. Phosphates will stunt the growth of Small Polyp Scleractinain (SPS) corals, meaning the coral cannot properly grow.
Second,
You'll be suprized how far away Aiptasia anemones can sting. I would recommend injecting the bugger with some Limewater or calcium hydroxide.
To answer your questions,
You're best off giving the coral strong amounts of current, preferably currents which alternate.
Your Acropora will also benifit from regular feedings. Their zooxanthellae only supplies the corals with carbon. The coral's nitrogen needs must be obtained through regular feedings. Acropora can get over 100% of their carbon from the light, depending on the species and the habitat in which they came from. Acropora esspecially are very active feeders, which do best with some supplied food.
I like feeding many of my corals Golden Pearls. This is highly recommend. Phytoplex could also be used for feedings.
FWIW,
I have almost no doubt in my mind your coral will durn a nice dull brown coloration under your current lighting, within a couple weeks or so. This is common when people are housing SPS corals under florecent lighting. This brown coloration is caused by zooxanthellae increase, which is used to capture as much light as possible. Polyps may also be shapped different to attract more lighting. Often times polyps turn extremely fat.
Regards,
Graham