john76, you are correct in that you really can't use incremental for those situations. However, it is generally good for things like sales, where you shouldn't do corrections, but rather have returns, which are a separate transaction. Cubes for things like GL, bank balances, Inventory, and similar "running totals" should not, generally, be cubes.
Most of my experience using incremental cubes had to do with sales, purchases, and insurance claims (similar to invoices) and we would update the cube monthly after accounting had "closed" the month.
Sometimes the grass is greener on the other side because there is more manure there - original.