The Margaree is a special place. You will find that most anglers are friendly and welcoming. Yes pinched barbs are fine as long as when you can pass the hook through your shirt lets say and remove it without hanging up. The angling is start at the top of a pool and move a step or two with each cast. There are some big pools that are divided by a tree or a rock. You are expected to come out of the section you are in and get behind others who may be waiting at this point. I have been to the Margaree for the past four fall Octobers and have yet to hook up. The fish are there they just don't take the fly. That is my experience there others may differ. If you are there on October 17-19 there will be a function called Flies and Lies put on by Pieroway fly rods. Held at the big blue barn near the fishing museum.
I'm telling you about the division of the pools because it can become a sticky subject and some will argue their place. One guy argued with me last year ,I hadn't seen him there , he was well away from the river but when I stepped in he began berating me. I apologized and let him go. Sure enough he got a big fish and obviously he was the idiot he portrayed himself to be. This fella was going to drag this big fish onto a sand bar and possibly blind him in the sand. When the fish fought his way back into the river the guys rod broke, karma. I couldn't have been happier for him. Good luck there in October the river holds a lot of fish sinking leaders may help, I personally don't use them which may be why I don't hook up.
