Good Afternoon Maggiebro,
We don't know about the better exchange rate in Croatia but we do know that you cannot exchange on-board so we would advise you to exchange your currency in the UK.
You can use a credit card to settle the bar bill and there is no dress code. We hope for smart/casual but it is not enforced. There is a Captain’s dinner one night towards the end so I would personally dress up a little for that, but not compulsory.
In regards to charging your phones, you will need an adaptor for all electrical appliances. We advise a two pin European adaptor.
Kind Regards,
Mildred