I'm doing something like you with miki today, but at the end of the day I have to admit that this "easy management" is more work for me than the system I need because I'm wasting time finding a specific receipt or invoice.

I think your right with the minimalistic approach, I'm lazy and I will not use it if I have to do a lot to store a document.

I'm not quite sure if such a system is useful for the open world too but open-source it will show :P