Are chalk labels on food jars safe to use in the kitchen

Generally, aging/ripening squash does not pose any food safety problems. You can eat all members of the family. You just have to make sure that they are only overripe and not rotten. Rotten squash will have areas which are much softer than the rest, and usually somewhat slimy.

It is a different matter if you want to eat overripe squash. Both the taste and texture will change, becoming mealy, or soft, or spongy, and the taste can get bland. You can try cooking it the same way as young squash. If this doesn't work, you can also try some recipe which masks the taste and texture change, for example something involving a puree or a coulis, and adds spices.

Here is a link to the South Carolina Retail Food Establishment Regulation page. I'd recommend looking at section 3-302. It says that except as specified, you should separate raw animal foods from ready-to-eat foods during storage, preparation, holding, and display. If you can't find what you're looking for I would call them and ask them what the regulations are because laws can vary from each locality.

Personally, I would never store or work with raw meat anywhere near ready-to-eat (RTE) foods without sanitizing in between. Also, raw meat is a TCS food, is the cold table going to keep it cold enough? I guess it depends how long you're holding it for. If your establishment is constantly handling raw meat throughout the day I'd recommend having separate stations for RTE foods and raw meat (cross-contamination between the two is extremely dangerous to customers and it's better to separate them altogether). Hope that helps.