Regffee6

We are on Independence at the moment and there are two ATMs on board, one dispenses USD and the other dispenses Euros in €50 denominations which you then take to guest services to break into smaller notes. Maybe Allure will be the same when it is here for its European season.
We have also used ATMs on shore to withdraw money from our travel currency account.
 

I would highly recommend going to a currency exchange in the US (possibly your bank knows of a good one) prior to sailing for cash.  Check with your credit card company (or debit card if you choose to debit card) to see what their overseas transaction fees are.  If no fees, great!  If the fees are crazy, you may want/need more cash or travelers cheques.  
You can also withdraw cash onboard in usually USD, Euros, or Pounds but that's normally about it.  
What I would recommend is if your credit card has no international transaction fees, to keep small amounts of cash, and use the card for everything else.  If your card does have fees then its time to run a budget for what you'd like to spend money on, and bring that in the local currency.  If you need more you can always withdraw onboard, and then pay the fee.  

Not sure where your cruise visits but you will need to check the currency for each destination you visit.
Countries such as the UK, Norway and Russia do not have the Euro as their currency
As far as i am aware USD is not accepted on land 

We recently took a river cruise though Eastern Europe and needed 4 different currencies and ordered them from our bank. It took a couple of days to receive the funds. We had enough currency of each type, mostly for pin money. We used our widely accepted credit card with no fees for anything else we needed. It worked out great for us this way.

Most crews get paid in USD, this will be paid straight into their bank account and converted into their own currency
they use the tips they receive onboard for when they go onshore, so leaving $$ on a European cruise isnt ideal. 
Tips should only be given for good service and you give what you feel its worth. There is no 15% to 20% wriiten on the bill.
If you get a taxi and driver doesnt help with bags you dont have to tip, if service or food in restaurant is terrible then no tip. People want a tip they need to earn it ? 
 

Yep do this.  You will find most bank run ATM's throughout Europe do not charge fees like some here in the U.S..  So all you need to do is verify with your bank/credit union what (if any) fees are associated when using your bank card internationally.  Out of my two different credit union accounts, one was 1% and the other was 0% per transaction, so even if I used the 1% card I would still be cheaper than paying to convert funds.  Doing it this way ensures you only get charged the actual exchange rate and not an inflated one.
On a side note, when using your credit card abroad, make sure you select to pay in your home currency and not to have the business do the conversion for you as the store exchange rates will not be favorable.... to you.  lol
 

In Europe I have used ATMs to make withdrawals from my checking accounts in Euros.  Generally, the rate is better than what my banks offer.  I also take about $100 in Euros for the plane trip, just in case, which comes from my local banks.    I always keep my leftover Euros for my next cruise or business trip.  The only use of $ I have seen in Europe was at military PXs, but I imagine you could leave tips in $$.  PS.  When using ATM or even a train ticket kiosk, be sure to change the language to English, pick the UK flag, for example.

Thanks for the advice we will do exactly that.??