I have failed to reproduce the issue on my own. This has something to do with the state of your wallets. I'm going to need more data to figure out what's going. For starters, delete the .lmdb files in your datadir. They will reconstructed on the next run. See if that helps with the C++ signer.
Woot! Thanks, removing them, and with C++ signer, it worked.
Still have those 4 confirmed txs which Armory thinks aren't confirmed (and offers to bump fee). I'll append tomorrow this one gets similarly stuck.