Number 1 is the main idea. It covers what the rest are giving examples of. It is not one specific example but rather an idea.
I would say " if I could banish disease from the human frame, and render man invulnerable to any but a violent death!" because he is talking about taking away a <span>disease and make man immortal-ish like.</span>
Answer:
Thoreau is saying that it makes no sense for a simple man, who had nothing to do with the formation of such a beautiful pond, to name the pond. Giving the pond such a simple name as "Flint's Pond" is discrediting all of the beautiful animals and beings who dwell there such as the ducks, the fish, and the beautiful flowers. The pond was named in the selfish thought of money, rather than majesty.