Most of the chemicals listed are caustic, or toxic, and best used in a Chem lab. Others, may be found in compounds that contain them. Key word there, being compound. I don't think I'd want to cook food with some of those compounds gasses (or fumes), especially near food or water that I'd want to consume.
You are unlikely to find any of the listed elements in their pure state. All will be compounded with something else.
Calcium can be found in calcium chloride. This is a drying agent. It should burn brick red.
Boron can be found in boric acid This is in some roach killers (labeled boric acid) and flame retardents. It should burn bright green.
Iron can be found as iron oxide. This is rust. Try a powdered rust. Be careful grinding metal powders. Better yet, find some rust that is already powdery. It should burn gold.
Potassium can be found as potassium chloride. This is found in some health food stores as a salt substitute intended for human consumption. It should burn violet.
Sodium as you already know is found in sodium chloride. This is table salt. It should burn bright yellow.
Think of all the fun you can have burning a differnt color flame every night.
All of these are readily available in many stores, none of these are caustic, and as I used to tell my students, all are less hazardous than gasoline. Many people use gasoline and white gas stoves with no ill effects. Use your head, but please don't be afraid of chemistry.