Moisture and heat are bad news... both shorten shelf life and can affect taste and texture (as can too much cold + moisture... which is why you don't keep chocolate refrigerated). Cool and dry are the best conditions.
You probably don't need to provide nutrition info if you meet the small business exemption criteria (although, most consumers and stores prefer that all products provide it). See here:
http://www.fda.gov/Food/LabelingNutrition/FoodLabelingGuidanceRegulatoryInformation/SmallBusinessNutritionLabelingExemption/default.htm
"One exemption, for low-volume products, applies if the person claiming the exemption employs fewer than an average of 100 full-time equivalent employees and fewer than 100,000 units of that product are sold in the United States in a 12-month period. To qualify for this exemption the person must file a notice annually with FDA. Note that low volume products that bear nutrition claims do not qualify for an exemption of this type. "
You can file for the exemption online.
Also, if you ever plan to package the individual chocolates not mixed, then it is good to have the nutrition info done for each separate variety (which you would need to do if you package them mixed anyway... to get the composite value you'll need the individual values).
