The primary feeling I get from using LaTeX is: fear. Any little special thing I adjust tends to break the document, or move figures, or fixing one thing breaks another and so on. And forget about changing templates.

My general advice here for you and many others in this thread would be to switch to Context (or even Luametatex if you really want to make some truly crazy stuff, basically it's just a newer and more experimental version of Context) if you are not happy with things and like to do your own customizations and don't bother becoming a TeX wizard. Latex is super if you are fine with the template you are provided or you absolutely need some obscurish package, otherwise Context is similar enough and bending it to your will is pretty much how it's supposed to be used.

My paranoid workflow is that I have to make many subdivisions of the document so that I can trivially enable/disable components when I am triaging a problem. When something breaks, I am less reliant on the garbage error messages.

So the top-level document is just a long list of inputs

  \input{intro}
  \input{prelude}
  \input{complex_figure1}
  ...