Wouldn't wish to comment on the actual question as that is one for the professionals, but would like to observe in relation to the US situation 411A raises that the US tax system is unusual in that they consider any income earned worldwide by a US citizen, or any income worldwide earned by a non-US citizen living in the US is liable to tax. Most countries operate a reciprocal arrangement so that as long as one or the other gets you then both are happy. Thus living in The Netherlands but renting my house out in the UK, I am liable for UK tax on my rental income, and NL tax on my salary.
Thus in our company any US expats get a different pay package to take account for the fact the the US authorities and the local authorities will both want a chunk.