Hello again,
Good idea, the duplicate functionality will certainly be implemented soon, might be very handy indeed! I'll think about the column hiding functionality too, although it is already possible to hide them by setting column2width=0 and column9width=0 in settings.conf
There is no risk of a future database not being compatible with the current one; I've already built a basic framework for incremental database updates and will keep supporting older instantiations. For example, a DBGL 0.2 database should be automatically upgraded to version 0.52 on the first run.
About the images: running executables inside zipfiles or images can be done using the following syntax:
archive.zip\mygame.exe
or
image.iso\mygame.exe
I have specifically added the grab buttons for this, for comfort. Unfortunately, it is currently not possible to navigate inside those files in a cross-platform way in order to select the game/setup executable. I'm planning to at least build this for zipfiles, since Java has support for zipfile 'browsing' out-of-the-box.