Could you please add a "Fixed" attribute to Category to mark items that are considered Non-Discretionary Expense items. If you can then allow that attribute in reporting you can breakdown Discretionary vs Non-Discretionary expenses to see where you are spending above or below.
This would be helpful as in the case with Bank accounts and credit card where some expenses are Non-Discretionary (must have like mortgage and utilities) and others are Discretionary (Shopping / Amazon, etc…