Hey Jeb. I'd contact Armalite directly about the rough feeling trigger. They may be able to take care of that for you. The 2 stage trigger in my SASS (factory....haven't changed it out yet) is "buttery smooth". No grit, roughness or slop. As far as outfitting the thing with a red dot......I'm guessing that you have Popeye arms. <laughs> The SASS (mine at least) tends to add up in weight once you start fitting it out with accessories.
Break in. Well, everybody has their own opinion when it comes to break in. Armalite suggests the shoot, wet patch and brush method for the first 40 to 50 rounds. But, as I said, everybody has their own thing. Either way, you won't be disappointed. The AR-10 SASS is an outstanding weapon.
And just to give you some ideas............................................................