I have not done a degree, but as for the exams, they are not particulary hard, really. The multiple-choice format ensures that you don't have to have a solid understanding of the subject to achieve a solid pass. If you have attended the lessons, completed the progress tests, skimmed the book and done some feedback you should pass most tests without any problems at all, even if you don't feel that you genuinely understand it all. The questions asked are often pretty basic anyway and it's far from how I imagine university studies to be.
I think that if you have a degree, any kind of academic degree, you will have no problems whatsoever with the ATPL exams.
Good luck!