A rangefinder might be the way to go if they work for you. I wouldn't switch for the lenses unless you have a specific lens you were going for. It would be horrible move if you don't mesh with the rangefinder mindset. Especially if you shoot a lot with the 85 mm. You can certainly do that on a rangefinder, but some people find the experience suboptimal.
Sure, something like the Leica 50/1.4 ASPH might be a better performer than the Nikon 50, but at $4k, it should be. And I bet you wouldn't notice that increase in performance in 95% of your pictures, particularly when hand holding your camera.
As far as CV lenses which fit your requirements, you are looking at a decent amount of money for a fast 50 and 35. The 50/1.1 and the 35/1.4 seem to be nice lenses, but the 50/1.1 is ~$1k, while the 35/1.4 is $600. Factor in the camera too. If you could find a CV 50/1.5, you might be able to get that for cheaper, but it's been discontinued. There's also the 35/1.2, but that's over $1k. That's a lot of money when you seem reasonably happy with your current gear and can instead upgrade it. Unless you get a chance to borrow someone else's rig, I'd say stick with what you have. I'm not super familiar with Nikon lenses, but if you want a sharper 50, and Nikon makes a sharper 50, why not just go for that? Ditto on the 35/1.4. You can also look into the Zeiss lenses for your Nikon (not cheap, but good). Maybe the 50/1.4?