Rabicano and Roan are completely different. I have several sabinos that are just sabinos, and I have a few sabinos/rabicanos.
Connected? Hard to say. Why would one show up without the other then? I've seen a lot of rabicanos without any sabino markings, and vice versa. I think it's luck of the genetic draw. I don't think they go hand in hand.
I actually see quite a few photos of paints with similar markings. And I always assumed they were frame. But frame alone (so they say) doesn't cause face and leg white. So obviously sabino is happening too. So if you get a roaned out "frame," I wonder if that is what sabino does to frame (makes the edges of the spots lacy), OR is it sabino alone causing this pattern?
Re the orange. Frame does cause face white. Spice, a member's horse on here, is a great example. Her only white is her face white, and she is frame positive. The only clue was in her face white - frame likes white to spread horizontally, including when it is on the face, especially above the eyes. I suggested her owner test her, and it turned out she was positive.
As another thought, I have a feeling that when they isolate rabicano, it too will be a KIT locus mutation. It too has the similar feel to it that the other KITs share.
I agree with this as well. The KIT locus is pretty neat the different genes on it can cause little white markings to an almost completely white horse like my sorrel DW paint Pepper. White patterns are so fun and unpredictable.