Why is the commission added instead of deducted?
The commission is calculated such that you see the amount you will be deducted from your account when using your credit card.
Where is interest of having the old currencies of the Eurozone?
Although those currencies are not in use, they are still use as a reference (during conversation) for large amounts.
How long is kept a currency I have modified?
Each currency update refreshes the rates with the latest values, so your modification is kept until the next refresh.
Can I disable the rate update (refresh)?
No, this functionality will be available with the next release.