I would rather build than design. Most of my designs seem like they would look better if only I had.....
My Engineering Brain says to make the bottom piece solid to Prevent having to clean under it. If you go with the arch, which I also like, I would consider placing a piece parallel to the front recessed about 4" and painted black to make it less visible. It would corral the dust bunnies to the front four inches.
On the doors, if they are glass, and maybe if they are solid panels, I would make the bottom rail wider than the top rail and I would make the hinged styles wider than the center styles. I would make the hinge styles something like 2" and the mating styles about an 1 1/4" each so they would block less of the view.
I have built a cabinet that has arched door rails at the top and I like it. I like the arched grain you have chosen. I did not think of that. Mine have a single arch that reaches across the top of the doors and is split in the middle.