I realized today that I shouldn't be so worried about how the code in my .emacs (well, .emacs.d/init.el) file is structured, or how general the code is because it's my personal preferences. I think this was holding me back from customizing Emacs all the much over the years. I was paralyzed by notion that the code had to be general, in some way, in case someone else uses it.
The hell with that. First of all, I don't share it (which may change) so why should I care? Secondly, it's not worth it to try and make code that is meant to accommodate my personal preferences immediately usable by others. It's usually a massive effort and what's the gain, really? Not much.
This is a bad mindset of mine: wanting code to be in some reusable form such that it does not require modification by others to use. I've recently starting thinking about the divide between "personal" and "public" ("corporate"?) code and how they seem to be at odds. Personal code should be readable or editable, but it doesn't have to be reusable.
Whether or not all code needs to be shared, well, that's a different story.