Will I lose my first-time buyers allowance if i go travelling?

What's wrong with relying on an educated opinion? Its surely a lot better (and should be a lot more useful) than the alternative which you recommend, of getting an off-the-cuff comment over the phone from a Revenue official.
What alternative did I recommend? I agreed that they should seek professional advice, warned that it was just advice and not a legal defence and offered my opinion.
 
I agree with you, which is why I agreed that professional advice should be taken. I was stating the obvious for the same reason that you were.
 
Did you? You suggested going to Revenue for "advice". As Clubman said, Revenue do not dispense advice (much less "professional advice"), merely information.
He did:
I agree that a professional opinion would be a good idea but it will still be a grey area no matter who is consulted. BTW I have found Revenue very helpful for information and advice over the years.