Re: Converting FAA ATP to JAA ATPL
I myself had gone through all this before trying to figure it out through numerous calls to the CAA in England. If you do a search through the Rotorheads Forum you will find the answers to your questions, but to cut it short there is no short cut!
As it stands last time I was investigating over a year and half ago, you will have to sit all the exams and possibly do some flying time. The CAA told me the amount of time required is up to the flight school, so pick a school that is honest and not gonna stiff you. It could be 5 hours or 30 hours.
There are numerous options to getting the exams done. Going to a crash cours for 6 months or so at Cabair or Oxford, or doing the online version which would take about a year. The best I have heard for the online training is Bristol.
To answer some of your questions you need to explain what citizenship you have. I gather you are most likely a European who went to HAI or something and on the 2 year work visa. There are many options out there, and it all depends where and what you want to do.
Good luck!