Firstly, just as in the US, you will need the right to live and work within Europe to be employed here. There are some exceptions, but they don't amount to permanent employment within Europe.
Secondly, you cannot fly a JAR or other European-registration aircraft without the appropriate European or JAA licence.
Thirdly, there are a number of N-registered aircraft in Europe, but they are primarily privately-owned bizjets. The one exception I can think of is the Atlas air cargo operation out of Stansted, using 747s. There may be others. I believe the Atlas operation has caused a great deal of controversy both here and in the US, and I suspect that it may be fairly short-lived, at least in its current form.