Thank you very much.  I had exact same problem (ArmoryDB not connecting to bitcoinABC) and was struggling since months.  Could not figure out I had to downgrade to an older version, was quite doing the opposite (looking for the latest versions of everything).
Now I hope I can finally spend my BCH.

By the way as you asked how to improve your guide you may want to detail how to get the sources of the v0.16.1.0 version of bitcoinABC (I'm saying this because, differently than Armory which gives step by step instructions for this, I could find no similar instructions for bitcoinABC)..