You're going to pick up most of your weight during the glassing if you do it right. On this plane I'm still looking for average. But as long as you sand off EVERY coat of primer all the way back down to the weave, only doing minor leveling as you go, you won't pick up more than 2-4 ounces during paint. if you do the glassing exactly like the method shown on my site, then you shouldn't pick up more than a few ounces there either. 6-8 ounces total is acceptable, much more is getting a little heavy. You should still be just fine, but the plane could be higher in the 10s than in the low 10s or 9s. FWIW, I've flown this plane everywhere from 9.75lbs - 10.75 lbs, and in my opinion it flies better overall being about 10.5 lbs. I think even at 11 lbs with a DZ you will have no issues at all. It's a BIG plane and already flies like it weighs 8 lbs. I won't debate the benefits of being lighter just because, but in all honesty I like this plane a lot better at about 10.5 dry.
But, the weight thing is a game that's played from the first piece of wood you put on a scale, and every screw, every single piece of equipment you put in the plane. Generally speaking the cheaper you are, the heavier the plane will end up. Same goes for geting complacent at any stage. "good enough" probably isn't. You're building a competition weapon, so take the extra care to make it as good as it can possibly be.
Sanding this monster can wear you out. So my advice is to just take your time. Sand it, take a break, sand it some more later...and then when you think you're done, go back and sand it some more. One thing about epoxy based stuff, it doesn't sand like urethanes. So be prepaed to put some effort into it.
I generally recommend monokoting the wings and stabs. It's just too easy and you can save some weight. But if you do decide to glass and paint them, realize it's going to weigh more. How much more depends on your technique, skill and determination.
The scale and the sanding blocks are the 2 most used things in my shop. Once you build a few planes, you truly understand why
-Mike