RJS7

No problems whatsoever, my passport with the endorsed visa worked just fine. 

The reason airlines do this is it their responsibility to transit a person denied entry back to their point of origin. So there a cost to an airline for ever person refused at the border - the airline has to send you back to where you came from, whether you can pay for the ticket or not. Ryanair do this all the time for non EEA passengers and they only fly shorthall in Europe. 

Thanks for the info folks, I have submitted the DS-261 and will go ahead with paying the fees. Good to know I can get the cover sheet separately from the welcome letter, I wasn't sure about that part.

Note that the US also provides for a foreign earned income exclusion as an alternative to claiming a foreign tax credit. This allows for the complete exclusion from taxable for foreign earned income (eg salary) up to a limit of somewhere around USD 120K to USD 150K.

Tell him the truth and you'll be fine. I got married in the US in last year, flying from Dublin. Told the customs officer straight off that I was traveling to the US to get married but would be back in Ireland 2 weeks later. He asked if both myself and my (now) USC wife live in Ireland (we do), what I do for a living and after that I was on my way. You just need to satisfy them you are going over for your stated purpose and that you won't overstay. I had a letter from my employer stating when they expected me back at work plus some recent utility bills in both our names in my bag. Customs officer didn't ask for anything bar answers to his questions.