Hey Wwilko,
Regarding passing your exams, from what I was told at the interviews the first time you sit an exam you must pass with 80%, if not, you get to re-sit the exam, but must pass with 100%...if not then.....It seems you go home

...its pretty standard, similar to the last airline I worked for. Dont worry yourself too much, because although the training is intensive, you should be fine with the examinations....as long as you put in the study required.
Goodluck!
Cheers