That is roughly correct, although:
The successor organization would still need its own proceeding where proof needs to be provided that the successor organization is actually successor of a banned party. But that's all that is needed to ban a successor org.
Yes - but if leading AfD figures were stripped of their right to vote, then such ruling would hit that person _regardless_ of which party he or she¹ is in. And it would also prevent those people from running as independent candidates. So I think going after individuals vs. going after parties is not an either-or. It would make sense to do both.
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¹ I don't think AfD has enby members.
@MaggiWuerze @Zer0_F0x