I've found evidence online illustrating that others are having the same issues as I have with ArcGIS Diagrammer but not any solutions. So, I figured I'd ask again.
I keep having problems with being unable to resize or move items beyond a certain extent within the design window. For example, I have a feature class with dozens of fields, but now it has reached a size on the page where I can no longer make it larger, so I can't see new fields I've added on the page. Also, I can only drag objects so far in the window before the program won't let me go farther.
I'm running ArcGIS 10.2.2 on Windows 7 (x64)