> Edit text without having to constantly move hands off of the keyboard home row to move the mouse or hit keys like PgUp/PgDn.
There's probably more you can do without using the mouse than you realize.
> # Change all the 'X's to 'Y's on the current line in 5 seconds.
In PyCharm, I can easily select the current line with Home followed by Shift+End, hit CTRL-R, X, Tab, Y, click Replace All. Doesn't really take much more effort than whatever black magic command vim uses.
> # Syntax highlighting for [any language the IDE doesn't compile].
Then you're using the wrong IDE. PyCharm is primarily a Python IDE, but also does syntax highlighting for JavaScript, HTML, XML, YAML, CSS, and CoffeeScript. Visual Studio Code supports C/C++, C#, CSS, Go HTML, Java, JavaScript, JSON, PHP, Python, and a few others.
Both of them have support for adding custom syntax highlighting.
> # Pipe text through an external program.
I'd be doing this on the command line anyways.
> # Start quickly enough to pop open text files whenever you need it.
I'll give you that one. But that's not enough to do your general development in vim.
I'm much more of an emacs than vim user, but the "wrong IDE" part is not quite true. Most IDEs support the common languages that you've listed, but once you go a bit further into domain specific, it is not as common any more. Speaking of what I'm familiar with (statistics), even SAS is supported in a very spotty manner, or at least was last time I've checked, and this is a popular language that has been around longer than C. At best you would get some limited R support, which really pales in comparison to what you can get in Emacs (and surely vim). Sure, sometimes they have their own IDEs (RStudio is quite good, and so is Matlab's IDE), but they have their own issues. I'm sure the same is true for lots of other DSLs.
There's probably more you can do without using the mouse than you realize.
> # Change all the 'X's to 'Y's on the current line in 5 seconds.
In PyCharm, I can easily select the current line with Home followed by Shift+End, hit CTRL-R, X, Tab, Y, click Replace All. Doesn't really take much more effort than whatever black magic command vim uses.
> # Syntax highlighting for [any language the IDE doesn't compile].
Then you're using the wrong IDE. PyCharm is primarily a Python IDE, but also does syntax highlighting for JavaScript, HTML, XML, YAML, CSS, and CoffeeScript. Visual Studio Code supports C/C++, C#, CSS, Go HTML, Java, JavaScript, JSON, PHP, Python, and a few others.
Both of them have support for adding custom syntax highlighting.
> # Pipe text through an external program.
I'd be doing this on the command line anyways.
> # Start quickly enough to pop open text files whenever you need it.
I'll give you that one. But that's not enough to do your general development in vim.