The usage between “etc.” and “and so on”

There are times where I would tend to favor one over the other, but I'm having trouble figuring out a simple rule that dictates which one I would choose. I would describe:

• The aroma of bread, coffee, and wine, but
• The scent of a skunk, a perfume, a flower, or a woman

Aroma seems to be the more natural word for describing blends of food and spice, while scent seems to be more apt for describing the natural smell of a plant or animal.

Also, not too unlike atoms and molecules, scents seem more fundamental, while aromas seem like more of a mixture or blend. So, I might talk about the scent of a particular candle, but the aromas of the candle store.

Still, the literature has plenty of counterexamples, such as the scent of bread, or the aroma of the flower, or the scent of the wine, so it would be a mistake to interpret any of these thoughts as "rules". The two words are largely synonymous, so there's plenty of room for overlap. If someone said that only one of the two words could be used in a particular context, I'd regard that as smelling fishy.

In the first sentence, the following is used as a noun.

EDIT: However, the most accepted use of below is as an adverb. (Up until today, I thought that it could function as an adjective, please see the comments below).

So in order for the second sentence to be grammatically correct, you would need to say,

Which of the sentences below is correct?

With the grammatical change, there is no difference in meaning, and either sentence could be used.