Can't help you with your first two questions (I need to know the answer to those myself), but for your third question, it says on my course (Biology) module list that you do around 100 hours of study for each 10 credit module. So if you have 25 hours of contact time (lectures, seminars, tutorials, etc), then for those 10 credits you'd do around 75 hours of private study/preparing for exams/etc. I assume that's a standard for all courses.