Not really, no. It’s possible, and I certainly could create some sort of script language. But much of the power of Keyboard Maestro actions comes from the UI of the action, the popup menus, etc.
If you want a scripting language, it’s probably better to just use JXA, and then have that ask Keyboard Maestro to do any of the tasks that it does that are hard to do in scripts. It’s easy enough to wrap the XML for an action in a function, and then you’re using a well known language.
Maybe one day I’ll do something to expose the actions directly to JXA or something like that, but definitely not this year.