At one time we had discussed updating various defaults for keystrokes, etc. I have run across an Akregator default change and can't find where we were listing them.
If I correctly understand your question, most defaults are found in *.ui files. For akregator there are several:
tdepim/akregator/src/settings_archive.ui tdepim/akregator/src/settings_appearance.ui tdepim/akregator/src/mk4storage/mk4confwidgetbase.ui tdepim/akregator/src/tagpropertieswidgetbase.ui tdepim/akregator/src/settings_browser.ui tdepim/akregator/src/settings_advancedbase.ui tdepim/akregator/src/propertieswidgetbase.ui tdepim/akregator/src/addfeedwidgetbase.ui tdepim/akregator/src/settings_general.ui
Darrell