None of it possible today. You have the variable #zzSeverity in certain situations to read and display the severity, but you cannot manipulate it.
Some of my plans for 4.1 is actually to introduce a BeforeAnnounceProcedure for punishments, to allow you to do some manipulation. Here I think you should be able to update #zzSeverity. Which can be quite useful to implement a good or bad mode of the Master/Mistress. You will also be able to set some variables, eg. change the text in lines to be written or instructions to be given.
I am also planning to give the BeforeAnnounceProcedure access to the punishment group used, and maybe other information about why the punishment is given. To give a better possibility to "make the punishment fit the crime".
I don't think you will ever be able to change an existing punishment. I don't see how it could be implemented.
These are my plans. However, the first function I will implement, is a Case=Random. I have been missing that. And it requires more changes to the program than you would think at a first glance. That is why I have started on a new release, 4.1.