Yes, you can, as long as you are able to program / have a programmer to hand / can pay someone to do the work. Building a system like that is complicated, especially give that such a system would typically be hosted on a network, possibly on the public internet, you'll probably want user-management and you'd need good security practises in place to prevent database pollution / data leaks. All of the source code for the AAT and the SCO contents (Adapt Framework) is freely available online and to modify as you see fit.
> Also, is there some way that I can set the value of cmi.score.raw programmatically and NOT through an AAT-created quiz?
Without trying to sound repetitive [see above] and yes, `Adapt.offlineStorage.set('score', current, min, max);`
> As for repeatedly playing an audio file etc., there are specific pedagogic uses where it may not be possible to place the control entirely in student hands. I hope all of this makes sense.
Yes, that makes perfect sense. As yet, no-one I know of has used the Framework for teaching languages. It would be some custom behaviour, probably a custom commissioned component or extension to make your requirements easy to replicate. You would need a good idea of your design requirements before asking someone to construct said plugins.
As a wider point, Adapt Framework and AAT are really the foundations of a product or service if you have the means and intent to produce something more custom or for a specific use-case. For a large cohort of corporate / public service / private education e-learning needs, it is used extensively as is.
I hope that helps some,