The choice between hot sauce and chili sauce is ultimately a matter of personal preference and depends on your desired heat level and flavor profile. Why not experiment with both to find your personal favorite?

So, if bell peppers are in the same scientific classification as cayenne chili pepper, why aren't bell peppers hot? It comes down to a chemical compound called capsaicin. This chemical is the sole reason why a jalapeño is spicy and bell pepper is not. A bell pepper has no capsaicin. Capsaicin attaches itself to the mucous membranes in our mouths which in turn send out the fiery sensation. That heat in your mouth (or hands) will vary greatly depending on what type of chili pepper you've eaten. Peppers are ranked by their heat, or the amount of capsaicin they contain, on a scale called the Scoville Scale. Their capsaicin concentration is given a number on the scale and it is called Scoville Heat Units. Bell peppers do not have capsaicin, so they have zero Scoville Heat Units, therefore they are way at the bottom of the Scoville scale. 

Crushed red pepper flakes are basically just dried peppers that are not ground to powdered form. Because it has not been ground further, it will leave you a mix of seeds and pepper flakes. This condiment is often used to garnish pizza, soups, and stews to add a layer of spicy flavor. That said, it might not be a good backup for some recipes because of its coarse texture. The good thing is you can always use your handy spice grinder to ground it into powdered form.