Good posts, thanks for the information.
One comment: I believe you are mistaken when you say that "BP replicas are not firearms. You do not need to legally do this with them." The classification of bp replicas as 'non-firearms' is only by the BATFE and only for the purposes of transferring them. Some states, but not all, also use that classification with regard to registration requirements.
I assure you that TSA, the FAA and the airlines do legally consider bp replicas to be firearms and require they be transported like any other firearm.