The "job" name is Ankoku Kishi (Dark Knight) so I would wager that the name might have been an early development name for who we now know as Cecil. OR it could have been the dev name of a different playable character and it was chosen for being (tied for?) the longest to make sure the spacing of the text and windows looked ok. The "all zeros" look like they're there as placeholders for spacing as well.
The portrait definitely shares elements with what we're familiar with for DK Cecil's portrait, but also with Kain's portrait. I wonder if they were both originally based off a single character?
The top left says "New Game" and the box below it has "Save 1" through "Save 4", also the box at the bottom says "Is this data ok? Yes/No", so I think this is the "load game" screen (the one immediately after the title screen).
Second picture (the shop) looks pretty much exactly like what was in the final product. It's completely populated with 0 Gil Crystal Shields though LOL.
Third picture looks like there were going to be four options to choose among for button layout. The first one is (mostly) what we're used to. A is confirm, B is cancel, X is menu, Y is "all cancel"?? The others are stepwise counter-clockwise rotations of that configuration.
Re: FF7 SNES -- I wouldn't be surprised if they were going to originally attempt to release FF7 for the SNES-CD / Nintendo Playstation.