[MainlyFlute]

I will point out that anything below G on the staff will not be well heard unless the rest of the group is playing quietly. Personally I love the low register of the piccolo, but that's not what it's used for.

True, but when it's tutti it's fine to have the piccolo play along and have more to do, just adding a bit of color. It's a lot of what flutes do as well - serve to add some color/texture rather than being heard per se. For the piccolo, being able to play along is better than resting.

The real question is what quality you're seeking. Where do you want that high-register piccolo sparkle? For those spots, bring it up an octave. For example, mm. 33-34. It could be low register where you have it for blended color and a homogenous sound. Or if you wanted that sparkling top line you could put the piccolo up an octave.

I agree that it's totally playable and looks like a plausible piccolo part. A bit on the low side but not unusual all the same.