Sandy - With Hasselblad's CFV digital backs (made specifically for V system bodies), there are no cords necessary. The same mechanism that triggers a film back also triggers the CFV digital back. No cords needed.
However, if shooting cordless, the CFV back has shutter speed settings that need to match what you have set on the lens. For speeds 1/8 sec and faster, there is no need to change the setting in the back, but for slower shutter speeds, you need to reset the CFV according to the lens shutter speed. If this is an issue, then you can connect one cord from lens flash sync to the CFV back, in which case you don't ever have to adjust the shutter speed in the back. Being an outdoor photographer, my shutter speeds can be all over the board, so even though I can shoot cordless, I always add the single cord, thus not having to concern myself with adjusting the shutter speeds on the CFV. Shooting with this one sync cord is not an issue, IMO.
I shoot with a 501CM, and CF lenses. I have the original CFV (16mpix) with large 9 micron photo cells. It is provides the cleanest images I've ever shot. The current lineup of CFV backs includes a 39 mpix and 50 mpix. Note - the 16 mpix back provides the typical Hasselblad square image (with a 1.5 lens factor). All the larger backs (CFV39 and CFV50) provide rectangle images (645 proportions, with very little lens factor, maybe 1.1), but can be cropped square if so desired.
Concerning focusing, I'm not sure what you mean either. The accute matte screens are as bright as anything on the market. The prism finders DO darken the image a little, plus provide a smaller image, both of which may challenge your focusing skills slightly. There are a couple of very bright finders made for easier & more accurate focusing, but at the expense of a reversed image, similar to the standard waist level finder.