All correct, apart from the exams example. 'I'm happy about your exams.' is ok. As Joseph said, you probably mean 'exam results', but in the context, it's clear what you mean. You wouldn't say 'I'm happy for your exams'. As in your first example, you can use 'happy for' followed by a person, but not usually by an event, situation or object. In this context, 'happy about' is the correct form - 'I'm happy about your new job'. for example

They are all correct well done! One small thing in the second one "I am happy for your exams" is not correct - why would you be happy for the exams? You would be happy for the person who has finished the exams. :-) not the actual exams themselves. "I am happy for your exam results" "I am happy for you, you passed the exams"