Hey Neova,
This will be done in the same resin that Rohby has used with the JM backups, sharpener pilots and the TV hand recasts, I believe is the Smooth-Cast 310. As for the weight I think the weight difference will be a mere fraction of an ounce and wouldn't weigh the FP anymore. Though I can't be sure. I have a package scale at work and maybe I can take it there one of these days and compare. I don't see any foreseeable dust paricles coming from the missiles. I guess it all depends on how many times you remove and replace the missiles on your 1/48, and I think it would have to be a ridiculous amount of times before you see such effect. My suggestion would be to wait and see what the other members say about the recasts before ordering it. Hope that answers your questions.