I've been asked about this twice this week so I wanted to write something quick on the topic. The short answer to this is: No.
The somewhat longer answer as to why is the following. Very similar to how Microsoft does not support the editing of a component binary (aside from various ISV/IHV partners), we do not support the editing of package or component manifest files inside of Windows installations that utilize the component store. There are several reasons for this but the main one is system stability. While it may appear that there is only one or two dependancies on a particular manifest when its been opened, the reality is there may be many more parent-child relationships that are not seen. Attempting to modify this in any way could potentially break servicing scenarios for the system moving forward and could result in system problems that will end up being extremely hard to track down.
I know that many customers attempt to utilize this type of mechanism so that they can lock down a specific set of roles/features. Right now, thats best done via Group Policy or access restricitions. Also, there isnt a way that you can restrict the local administrator on a machine from anything, that's usually asked in conjunction with this question for some reason. If you dont want someone being an administrator on a machine, dont make them one. While technically we would support you in removing the manifests from a mounted .WIM file, if you were to encounter a problem with the installation once it was deployed, we will typically ask you if a RTM installation of Windows functions properly. If it does, then we usually conclude that there is something wrong with the creation of the image, and in this case we would know the root cause.
So, please dont edit these files. They are there for a reason and there are usually other ways for users to be restricted from using the things in Windows that you might not want them to.