MasterPassword 5 incorporates many of your suggestions, like a new interface, easier but complete, or the support for more than one username per site.
MasterPassword 5 will bring you videotutorials. As you suggested, help section will be more simple.
Some new features:
-New User interface: easier, faster and safest.
-More than one pass per site.
-Multiplatform file (now, called BrainyBackup) much better.
-Customizable character sets.
-Stronger passwords (SHA512).
-Native support for security answers.
-Code optimized for faster updates.
-And much more.
Of course, if you do not like the new interface, you can go back to the old one downgrading from the Settings menu. However, you will not enjoy new features.
Hope you like it.