You will be fine. Just get a smaller one, maybe 4", and just let it be. However, depending on how stocked your tank is, just be forwarned that it will probably kill most corals that it trys to get passed when finding the spot it wants to be in.
I would say you could really just feed it for maybe the first two weeks of aclimation, and then stop. I haven't fed my RBTA for about a month now, and having stopped feeding it, it almost looks happier and more colorful than its ever been- real sticky too. But maybe feeding it once a month would be a good choice, just so it can eat. But that way it won't grow too quickly.