1), When moving the SS I do not normally recommend using the -j option.
2), Are your configuration policy’s defined at the ES, if yes then they will be the same. Else, the system will get Default and any specific polices from the new DM.
3), Its best to delete all SD jobs for the Agents prior to the move of the SS. Only move one SS at a time.
4), It depends on the performance of the DM’s and the number of installed packages. These two configuration settings effect the performance. Increase the Time Limit and decrease the Time between to give more resources to the mover task.