Perhaps I messed up here... but I sent all of my BTC back to Coinbase... made a new B-Cash wallet & imported my BTC wallet.dat file and it says I have 0 balance.
Oh, dear. There are tools specific for this.
BUT... the final transaction to Coinbase hasn't confirmed at all since it happened on August 5th -- should I assume it will fail eventually and "return" those Bitcoin Cash coins when it does ?
They are two separate chains. Coinbase is only going to give you BTC because they did the splitting internally and/or will provide the BCH credit before January 2018. If you had them on Coinbase, during the split, then they have stated they will provide users with an equivalent amount of Bitcoin Cash ... later.