I would also like to suggest a direction focus for the app. Making it a totally tag and rule driven model with smart folders and searches the means for viewing and temporarily organizing the data.
What if you got rid of the accounts formula and simply tagged everything to identify and access it. You would simply have a long list of different types of transactions and just use a set of rules or column sorting to get at what you want. iCompta already has some of this, why not simplify it further.
Just a thought
