> I have centered the "Change" and "Rating" covariates of interest for each level of Valence separately.
In that case I suggest that you specify a 0 center for those two quantitative covariates with -qVarCenters.
> So I should be using gltCode 3 and 4 as seen below?
They look fine to me.
Also, you need to specify the random effects, for example:
-ranEff '~1' \
Gang