You can always kill them in secret and never get caught, that's what is going to happen now, the ANC would no longer have their cadre deployment committee, they can no longer hold their cadre deployment meetings, (in public).
They will have to find discrete ways to deploy their cadres that would not arouse suspicion, like just declaring their cadre the best person for the job and appointing them over everyone just like how the DA is going about it, it's just a little inconvenience at most.
Yes, but it will be a lot harder to do and the clout of these deployees will be greatly reduced. They have until now benefitted from massive political clout. Remove that and the people that work with them can and will out them. This is why whistle blowers have had so little protection in the past. A dedicated investigative unit going after these people will probably be required (Scorpions).