Hi Eric,
I hope you are doing well.
I just ran into the exact same issue, trying to use an exported vCD vApp in VMware Player.
I only wasted an hour though and then found your detailed and matching problem description.
Therefore, I am not crazy and it is just a VMware software issue, I guess the VMDK metadata of the vCD exported vApp is just not compatible with VMware Player.
@VMware: Please fix this.
I will go your described workaround way now, via vCenter export.
Cheers,
JC