Even if you used a full pound of the chocolate, it would only account for about 6.2 % of your grist. Adding about 10.5% for the caramel malt you used means about 17% of your grist is dark grains.
Most of my stout recipes have about 15% dark grains in them including grains with Lovibond ratings higher than the crystal you used, and they taste good to me and some of my friends who like stouts.
If I bumped up my percentage of dark grains by another 2%, would it make my brew taste burned? I don't know.