My responses to all of the above (and once again, I am not urging you all to personally support sterilization--I know it is against Judaism; I just want you to take a "pro-choice" attitude towards it since it is voluntary and nobody is being harmed)
1: I agree, exiling scum is much better than sterilizing them. Sterile human filth can still rob, rape, murder, etc.
2: I agree that male sterilization (the vasectomy) is medically preferable to female sterilization (tubal ligation), but most men--especially primitive Third World men who know nothing about anatomy--think it is an emasculating, feminizing procedure just like castration. Most would never go for it.
3: Who cares if Amalek takes money in order not to spawn any more devil-children?
4: Even for non-Amalek, this could be a good idea. Many dumb people wind up, for whatever reason, having more kids than they can afford. Even if they are decent parents, it is still an enormous strain and burden on their lives. Some of these unwanted pregnancies end up in the abominable crime of abortion. JTF should support anything that lowers the abortion rate.