Should I focus my course selection on topics covered in the bar exam?
Don't focus on these courses with the intention of helping you pass the bar.
The best way to prepare for the bar exam is to take a bar exam prep course such as BAR/BRI. These courses are designed to make sure you get enough knowledge in the bar exam areas to pass the bar and retain it long enough to pass the bar.
However, if you're not sure what topics interest you, picking bar-related courses would give you a good taste of a lot of different areas; maybe you'll find something you love.