I found my A-Level computing class the best I ever did. What I have found is that if you get a really good teacher the experience will be worthwhile and rewarding especially if you want to do a Computer Science related degree. My teacher was through in A-level which allowed me to basically stroll through my first two years as an undergrad. It is however not required for entry for all universities I know.
As for the first question, the basic Computer Science degree is a start, then you can do the Business Studies and Computing degree at UZ which is fabulous (I took it), then you can also do Engineering degrees like Electronics if you're more on the Physics side. In the end it is just a matter of you making the most of your education.