Your killing me smalls! A complete list? Even I don't have one of those. The entire history of the mod is in the support directory in the form of changelogs. This is something of a challenge, to come up with a complete list, but I really hate documentation.

( hardly anyone reads it anyway

)
Offhand, changes can be classified into these categories:
- Campaign & flotilla
- Sea/Air Units
- Air power changes
- Player submarine
- Interior & crew
- AI unit and player damage model
- Deck gun and torpedo
- AI & ASW
- User interface & commands
- Menu/shell
- Graphics & sound
- Stock game bug fixes
I could probably fill a page or two listing changes in any one of those items except the menu/shell.