As a recovering M&A deal lawyer, I can reply to at least a portion of your question. "NewCo" is somewhat of a misnomer, since as a matter of deal structure, ECU will merge with and into Golden Minerals when the deal is consummated, with Golden Minerals as the surviving entity.

In effect then, NewCo is Golden Minerals, it's just that upon the consummation of the merger, Golden Minerals will have absorbed ECU in its entirety (assets, liabilities, the good, the bad, the ugly, the whole ball of wax). So the post-merger entity remains Golden Minerals, a Delaware corporation.

I will have to defer to someone a lot smarter than me on the question of how being domiciled in the U.S., as opposed to Canada, affects the company from a tax and regulatory standpoint, although I'm pretty sure that the location of the properties/operations and the applicable local laws are the most critical factor.

Hope that helps...