I may be stating the obvious, but I have noticed, completely by chance, that one can increase attribute values in order to make it possible for certain skill-books to be read and have those skills go up, and then go back and undo the attribute increase without decreasing the newly learned skills. In other words I may need to go up to 100 personality to reach 210 mind points by reading from a book, but then I can decrease personality (and recover attribute points) and still keep the 210 mind points.
Is this an expected behavior? Is there any technical harm in increasing/decreasing attributes this way?