Although those all sound like interesting enhancements, the result is a bit different than an "unbuffered" prototyping board. I'm really interested in retaining the maximum amount of uncommitted sea-of-PTH and minimum commitment to additional circuitry. Ideally that would include reducing the current commitment to three voltage regulators. Perhaps one or more could be jettisoned?
It's, of course, your design. So I'm "holding tight" until seeing how much real estate gets chewed up by your additions/modifications :->.
I don't s'pose that your potential supplier would accept two designs to split the 100-count?