EDIT 15-08-2018:
The behaviour looks somewhat changed. I now use Mx 7.13 and may view the createdDate as long as I have access to the object, that means: some access is granted, like creating / deleting / read an attribute.
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It is currently not possible to expose these system attributes to users which don't have the module role System.Administrator
Upvote this idea to get it on the Feature Request agenda of Mendix
1 - open the entity, access rules, give read access to the module role.
2 - check whether your user role is checked for the module role of 1
You could make two attributes in the entity of which you want to display these values to achieve this: Changed_Date, Changed_By for example. When the object gets changed you write the [%CurrentDate%] into the Changed Date and retrieve the name of the user who changes is and write it into Changed by.