Alpha Omega's LIFEPAC Electives are meant to fill in the gaps left by the rest of the curriculum. Using the same workbook approach of the core subjects, the Elective courses range from Home Economics to Spanish I and II to Art to Accounting to American and British Literature. Each subject has a number of consumable workbooks covered by a teacher's guide just like all other LIFEPAC programs—teacher's guides contain answers to written work and suggestions for discussion and extra activities, while student texts include all required text and written assignments.
The elective courses are for junior high and high schoolers (some were designed only for high schoolers) and are intended to be used in conjunction with the core subjects, not as replacement texts. Worktexts tend to be much more colorful and engaging than those for basic courses, while the text itself is generally more thorough. While many of the topics covered are interesting and important, none of them are "required" for high school, and are mostly intended to either fill up credit requirements or for students with specific interests in any of the areas covered.
If you're using LIFEPACs as the core of your children's curriculum, these would make good supplements. However, it would be just as easy to supplement with more thorough material on the same subjects, whether you're using Alpha Omega or not. The upside to the LIFEPAC system is that they're self-contained and you don't have to run around buying a bunch of extra stuff. At the same time, there are plenty of options for most of these subjects that offer a much more thorough introduction/overview, including assembling coursework yourself.