the two other books are memoirs, both edited by sam zinglersen, who was a long-standing friend of martinus.

How would the previous sentence be correctly capitalized?
Answer: The two other books are memoirs, both edited by Sam Zinglersen, who was a long-standing friend of Martinus.
for example, we use a large group of musicians and music lovers to test our speakers.

How would the previous sentence be correctly capitalized?
Answer: For example, we use a large group of musicians and music lovers to test our speakers.
lauriska , 26 years old, kirby hill, united kingdom

How would the previous sentence be correctly capitalized?
Answer: Lauriska , 26 years old, Kirby Hill, United Kingdom
and the rest, some on planks, and some on other things from the ship. so it happened that they all escaped safely to the land.

How would the previous sentence be correctly capitalized?
Answer: and the rest, some on planks, and some on other things from the ship. So it happened that they all escaped safely to the land.