I have had a GS Maroon for 3 years in a 29 gal. he is about 3.5 in long. Mildly aggressive at times, but only near his favorite spot in the tank.
Gold stripes are thought to be less agressive than their white stripe cousins, but I think it depends on the individual.
Not all maroons are aggressive. Just like not all damsels are aggressive....but they can be.
I have used the moving the rocks around technique and I do believe it makes some difference. But mostly the other fish just stay out of the Maroons space.
They are beautiful fish with a lot of character...very active and fun to watch.