Yes, everything you can do in VBA you can do in another language, and probably more easily. But then you have to persuade the users to use your app - if they're already comfortable with spreadsheets, VBA can make it easier to get them using your product.

If you can work your way through an intro book, it'll be super beneficial! Everything in either of those books will probably be useful at some point or another. No way I'd be able to do that in your position though. Personally the only way I can learn new technology is to have a goal that I find motivating (often, 'build a system that can solve some pain point in my life') and then identify the minimum useful step I can take towards that goal, and then mess around with books, forums, documentation, etc until I've achieved that step.