"Leaving aside crazy countries that use artificial gender selection technologies."

What happens when we can select the baby's gender (and a whole bunch of other stuff) before birth, using genetic engineering? By transhumanist standards, this is a very conservative prediction; I don't think it's "crazy" to develop or use such technology.

"Humanity is facing multiple species-level extinction threats right now, and I gotta tell ya, there ain't a lot of people steppin' forward."

In comparison to other groups with similar membership levels, we're doing very well. The National Space Society has more than twenty thousand paying members. They have an annual budget of ~$1000K. How much has SIAI raised so far this year, off a donor base of a few hundred people? $500K? $600K?

"We don't have a way to precisely copy macroscopic objects yet, but that might change with further technological development. Do you think that Molecular Nanotechnology is fundamentally impossible? If so, why?"

This is a giant cheesecake fallacy. We could, in the future, create a society of beings which are identical down to the last bit. I, and I suspect most other people, would find such a society highly undesirable.