Bob, I like your minimalist approach, it is probably what I would do from scratch, but since I am converting an existing Holley system to EFI on a timescale, I have thought about it, but opted for keeping the existing Low pressure system. In particular, the connected tanks idea still keeps haunting me, so I might do that later.
The first thing is that you are feeding the HP pump by gravity only, and the forward surge of fuel under braking seems to be a very real issue, if it does starve the pump, not only can you lose fire, but you can damage the pump. So you have to avoid this by any means.
If the inlet filter blocks, it will also cause the pump to cavitate, so watch out for that one.
The other thing I think you need to be sure of is being able to change filter or adjust something without draining the tanks and as a point of safety, fuel pickups are normally at the top of the tank, pipe dipping down to the bottom, so that any leak stops when the pumps are switched off. If the inlet side develops a leak, it could be unsafe as it won't stop.
I was surprised that you have foam in the small rear compartment, my DAX has the same small baffled compartment, but it is empty of foam I assume to allow a simple lever float level sensor to work there, with a baffle to help retain fuel under braking.
Dave