Very interesting to learn about specific problems! Having also been responsible for integrating the components and implementing the back-end has probably helped me avoid many of those problems. So it may be that this approach is best suited for very small and very large projects.

Thanks Tormi, indeed, I should have mentioned Compony, which is a relatively new (to me at least) approach to developing separate components for Drupal themes.

I really need to have a good look at Compony, especially to see how Compony components can be used beyond Drupal. It seems to be a unique, opinionated approach, in this blog post I was referring to more general common practices adopted by several projects.