I'm not familiar with many professional snipers, but, I'm not sure that their choice of equipment has a lot of relevance. I believe we are mixing two different things, the accuracy potential of the platform, and the relative difficulty each presents for most folks to shoot. I am convinced there is no reason a bullpup cannot be as accurate as any full length rifle, assuming the same degree of precision build. The only bullpup I own is a Taipan Veteran, and it is as accurate as my Red Wolf or RAW. With that said, in real world shooting conditions; i.e., position target shooting or hunting, I find the bullpup much more challenging to shoot well, in spite of the Veteran's excellent trigger. It's so short, that holding steady, even with available support (as leaning against a tree), is a lot more difficult for me. Benchrest competition is largely a test of equipment, not marksmanship, and with a good front benchrest or bipod, I have found the Veteran as accurate as anything I own. But, if I go walking in the woods, I'll probably take my Royale 400. It might not keep up with the Veteran from the bench, but for me, it's a heck of lot easier to shoot well in any non-benchrest scenario.
I have a different opinion of the rifle's weight. You express 7.5 pounds as a maximum for field conditions. For me, that as a bare minimum. You might walk more than I do when hunting, but a light rifle is a lot harder for me to hold well. My lightest rifle is a Royale 400. With scope, it weighs about 8.5 pounds, and I don't want it any lighter. Years ago I did a lot of quail hunting, which involves walking all day. I was talked into trying a very light shotgun. It was a dream to carry, but a nightmare to shoot. I decided I would carry what I could shoot.