goatpig, I think you nailed it!
I could not replicate any of the bugs I've detailed.
I've tested all the paths that led to the two bugs I reported and all ended up working fine with the current state of the testing branch, using the setup on testnet.


I  was also able to (finally!) unlock the mainnet lockbox.

I still have your testing coins. If there's anything else that you'd like me to test/verify - I'd be glad to.

Thanks again for your help