Hookay, wellp I've been trying to figure this audio bug thing out for like a week now. And almost as soon as I finally break down and ask for help (above) I figure out how to solve the problem!
So for anyone else who bumps into this I'll jot down what I did.
First, I installed the latest version of C2. This one has a new option (new to me) under the audio object called "unload all audio."
So just before I use the load game command, I use this new unload all audio command. I'm assuming this is clearing some kind of audio cache that may be building up over time and causing a lag in streaming audio? I have no idea. All I know is this is what has worked for me!
So hopefully this will help anyone else with a similar issue, if they happen to come across this!