Weight is kinda-sorta important in the hills, but not nearly as important as most people think. And most of the people who think bike weight is super important could stand to loose a few pounds from the gut, in my experience.

Rolling resistance, according to recent studies, is quite a bit more important than most of us had thought. Investing in a great set of tires would almost certainly net you more speed than investing in a latest-greatest bicycle.

Aerodynamics is crucial - but the rider is the critical part, not the bike. An aero frameset is worth three one thousandths of a second in a theoretical time trial to Mars (IIRC ) but rider position can make or break you. Get those TT bars!

Some people say the stiffness of a carbon frame makes cyclists much more efficient as compared with a "flexible" steel frame. I think those people are FOS, but impartial research doesn't support either camp.

Index shifting is critical to the criterium racer. Less so to the road racer. To the time trialist? Essentially irrelevant, IMO.

Short version - I'd keep your current bike, add TT bars and the fastest tires you can lay your hands on, and spend the $10,000 you saved on training and diet.