Hi Stan,
Thanks for the great post. Here put my 2 cents:
The top priority value by introducing BTCX fork to Bitshares is the accumulated network effect and brand by Bitcoin itself. For main stream crowd it greatly shortcut their way to Bitshares by saving a lot marketing efforts. So the target should be made simple and clear with this BTCX: with which to introducing Bitshares to people who know the legend of Bitcoin while don’t have a chance to own and trade. So why not simply push on the following and keep focus:
1-Leave those 51M potential UTXO for later claim ownership of their rights (account creation on demand), this just gives legit for BTCX in the bitcoin community. Raise no more expect, concern, efforts at least at current stage.

2-Do value the remain 50M unmined BTCX. They are the key to the way lead us to the main stream. Make good use of it for promoting people to their first landing to the crypto world, sure with the super highway of Bitshares’ network.
3-Do special handle whatever for BTCX, free trade for example, under current Bitshares architecture to make it happen ASAP to catch up current fresh Bitcoin fork events before its fade out.
4-Fund a developing efforts to put above in a simple and clear way. Keep focus on the benefit which Bitcoin brand do to us.