Great advice, Qatar Living, thank you.
On your point 4, all banks in Qatar ask that you inform them if you want to use your credit card before travelling. This is so that they can allow card transactions to pass problem-free when customers are spending overseas; a a regulatory requirement on all banks.
For Doha Bank customers, this can be done easily by sending an SMS with the words "MAG" to 92610 or by calling the Doha Bank Call Centre on 4445 6000.
This Summer, there's a very good reason to do just that because we have a great promotion which saves Doha Bank customers lots of cash on their summer travel spend.
For starters, cashback at a super rate of 10% can be had on Qatar Duty Free purchases at Hamad International Airport. In addition, we promise 5% on all international credit card usage e.g. purchases, cash withdrawals & internet transactions in foreign currency until 31st August 2015. More details here: http://goo.gl/PmYnmy . Recommend you read the terms and conditions section too for added clarity.
Bon Voyage!