Agree with Linerider. Get everything in writing and know how you can exit if possible.
With such a big investment, I would personally probably choose to stay closer to home at Easy if I were in your situation. European labor law will not protect you in Qatar. That said, QR could offer a great cultural and flying experience if you are open to it and you know what to expect going in. You want to understand how long you would need to stay to fulfill any obligations at QR in case you don't like it.... Examine the down side before signing anything.