Update #2: Printing Hiatus Resolved
Again, in the spirit of fair disclosure, I wanted to post that CreateSpace and I have resolved our issues. Admittedly, I had given up on them but a supervisor contacted me, explained my files should not have been rejected, and wanted to continue working with me.
Since I’m a sucker for well-meaning customer-service (in the spirit of solving a problem, that is), they’re back on my good list.
However, in researching other printers and trying to assess my needs, I’ve changed my physical print strategy in that I’ll only do digital single issue printing and paperback collections going forward unless it’s a special circumstance.