Well, this one had me in stitches so I thought I'd share the story.
First, it has never occurred to me to find out how many actions were in a macro but I thought it would be a nasty little problem to solve with all that nesting so I read along hoping to glean some juicy AppleScript and JavaScript.
But the command line solution by @JeffHester just tickled my keyboard and I thought why not turn that into a general purpose counter (not just macro actions)?
Well, there's a good reason why not, it turns out. Which is that grep doesn't return the number of matches but the number of matching lines. Which is fine if you're looking for ActionUID which sits on a line by itself in a .kmmacros export.
But as a general purpose tool, you need something that can find more than one match a line and has more robust regexp support. Which naturally made me think of Perl. So I wrote up a macro using Perl and it was fast and accurate and worked on .kmmacros files and everything else.
Then I slapped my head because the Concordance module in Literary Toolbox does exactly the same thing (presuming to ignore case). It's just called Concordance instead of KM Action Counter.
Which just goes to show how undervalued an education in the liberal arts can be. If one only knew what all those English majors know...