Good luck getting the first two passed into law, at least in the US. "Encourage couples..." will get no traction. We still have a ton of littering, and all the religious groups in the US (the Quiver Full movement etc) will love that. Cutting trade based on a country's birth rate and adding tariffs based on EI etc will be extremely problematic.

Sure anything can be done "democratically." But politics is the art of the possible...

Punitive taxation and restricting trade with Africa wouldn't be a good look...

https://en.wikipedia.org/wiki/List_of_sovereign_states_and_d...

(Not to say it's only Africa by any means, but you do have to go quite a ways down the list before you hit a non-African country).

Sure, but would it be worth it? I suspect yes; the alternative is continued population growth leaving very little natural world on the entire planet and all of us eating an industrially farmed diet.