My actually-concrete plans were to vaguely reference Roy's Theme a few times in his fight against Sabine and use two measures of Thog's as a sort of joke farther down the road. Also, I was asking this question in advance to any people who might be secretly working on a Haley/Durkon/Belkar's theme. Especially with Haley, I might have to completely invent her musical identity to properly incorporate her into my piece, and I don't want to step on anyone's toes if they're already working on her.
Fine with me.
Also, for those keeping track, stay tuned for Thog's theme.