In my experience you'd have to be very lucky to have the hinge mortises match and line up. Fortunately cutting them on only one door is a matter of a few minutes with a chisel and knife (use the knife to score the corners if your hinges have rounded corners). For the latch side you can probably use the pre-bored door and move the latch mortise as required so that it fits, making a "dutchman" repair in the door frame as necessary. Otherwise you can buy a door boring jig for ~$30 and put the knob wherever you want it. You can bore a door freehand, but the jig greatly reduces the chance for error.

I use Baldwin knobs. The half dummy is a small 1/2 inch bore hole similar to a cabinet knob with a small matching plate on the back of the door. This would be used for a closet door where you don't see the back of the door. The knobs come with a template for the hole. You just use a 1/2 inch regular drill bit, takes 30 seconds. My Baldwin full dummy is a spindle through the 1/2 inch hole with a fixed knob on either side. It looks like a regular door knob but doesn't turn so it is used on doors that you see both sides. I would definitely get a full dummy set for your doors since it is a passageway. Just make sure your guy doesn't drill regular bore holes in the door. I ordered closet doors prebored and am stuck using a regular functioning knob set since the holes are too big for a dummy set. I guess some dummy knobs must just get screwed on from the front? Maybe that is what you were looking at? I thought they all worked like Balwins.

If you asked me to set some temp plywood tops, I would put a couple screws in them to keep them from moving and possibly moving the drain lines on the sink. No reason to worry about filling the holes after the tops are gone. The new counters will cover them. The screws through the back of the peninsula cabinets should have been short enough to now come through the inside, or placed where you wouldn't be able to see/feel them. You should be able to take some nippers or side cutters and cut the visible portions of the screws/nails off.

Thanks, I'll check. I have the manual and don't see where to connect the sensors on the four terminals but as you state white to white and black to black. I hurt my hand so I won't be able to get to the task right away.