If you are in the early part of your career, my advice for you would be to keep your options much wider. You will be in a better place to identify your potential as you progress in your career, much similar to a practical experience as compared to the textbook knowledge. If you are already an experienced professional then my advice would be somewhat different. You should go after the job that doesn't feel like a job but something you love doing (... and then you never have to work again, as the quote goes). One of the important factors of loving what you do is to continuously learn new things because learning expands your limit of thinking and then the ability to organically take up new challenges. My other advice to anyone on the success path is to believe in self-potential. It is possible to achieve anything but only as long as we believe in our efforts and keep trying. If we don't fail then we didn't try, so it is perfectly fine to fail so long as we learn from failures.

I think that you should always be authentic. But that shouldn't be a problem if you identify with the TUI values and feel comfortable :-)

As Quality Assurance, we always work with that concept in mind: design, test, feedback. Don't stop any of these 3 things... ever. You can try everything; you can test and arrive to a result. If you manage to understand the potential to improve based on the result, you are in the right position to improve the quality. This will mean you have in mind the entire flow and things to improve. Don't stop yourself!