Digibud, sounds like that fulcrum wheelset is very tough to handle that weight you used to be at. I also have a Roubaix with roval rims. I run 700x25s on mine. I've tried different tires and they do make a difference on ride. The softer tires ride better like michelin race and conti 4000S but they cut much easier and therefore do not last as long.

For me, what has worked best for ride and flat protection are folding gatorskins and tire liners. Rode 8,000+ miles last year and only one flat on the road. I also have a new Surly LHT touring bike with 700x37s. It's a steel bike but rides like butter on chip/seal, really....so nice. Sure it's slower and heavier but very nice ride.

I ride a lot of chip/seal and have about 14K miles on mty roubaix bike in 20 months. I'd try different tires and pressures before investing in a new wheelset since you have not had any issues with the fulcrum and speed is not a priority.