I've had a few of them over the years in various tanks and I really like them. I think they are an underrated fish which is unfortunate. They are hardy, cheap and IMO quite nice looking especially when they get bigger.
They shouldn't bother any corals outside of possibly perching on them. They will eat anything they can fit in their mouth whether that be small shrimp or small fish. They aren't overly aggressive IME but that will depend on how big your tank is. IME they established a territory then they usually just defend that and otherwise go about their business.
If you have another fish with an established territory and similar behavior you may have an issue, again depending upon the size of the tank. You mentioned that you have a "purple basset" (I assume you meant basslet) though honestly I'm not sure what you're referring to. I'm guessing "purple basslet" refers to purple dottyback, black cap basslet, royal gramma or possibly chalk bass. In the past I have housed a harlequinn basslet with a black cap basslet and a lantern basslet. The harlequinn and black cap had some territorial disagreements (they divided a 125 in half and generally stuck to their respective areas) but it never ended in violence, just posturing and fin/gill plate flaring. The harlequinn and latnern got along alright, similar disagreements to the harlequinn and black cap but the lantern was much smaller so it always went one way. I've never kept a royal gramma (though I imagine the interaction would be similar), chalk bass or purple dottyback so I can't vouch for any of them.
They are fantastic little fish.