So, this entry is a little late. I took things easy today, and started messing more with vim. It's not going to be a drop-in replacement for Sublime Text in the ways I care about, especially not after the effort I put into customizing the syntax files. From initial looks over this stuff, I'm not at all sure it'll be possible to port over all of the stuff I want to have. For example, in my custom color scheme for Sublime Text, the contents of a string are slightly emphasized, but the delimiters are not. (Modulo various bits of special-casing, like that interpolated expressions are not emphasized, and neither are Python docstrings, which instead are internally highlighted as ReStructuredText.)
I tried getting hashed syntax highlighting working, and that was a disaster. I have some complaints for myself about how I configured it in Sublime Text, but the plugin I found for vim just has so much it does wrong, and I couldn't figure out how to mitigate it.
On reflection, I'm not extremely attached to the hashed syntax highlighting (I mostly don't mind either its presence or its absence, which implies to me that it would be a net good if I can fix some of the bad color choices I made), but the lack of emphasis stuff makes me mildly anxious. (I mean, I suppose I'm not using that on my work computer either, but...)
I should probably get more experience with this stuff before I toss myself onto VimScript, or translating VimScript tutorials to use Lua instead.
Anyway, it is way too late, I need to end this post half an hour ago.