There is no charge for using online banking, registration is free, but there may be charges for online transactions. If you qualify for free banking then everything is free. I will look at that link and see where if any confusion may arise.
I had a look and basically an online bank account is the very same as a cheque account in that you will still be charged a maintenance fee as per the terms. And you will incur fees for atm, direct debits and so on.
hope that makes sense. Your best bet is keep 2.500 in balance and its all free.