Learn English – “out of” vs. “among” vs. “from”

"One out of many" implies "One randomly chosen out of many similar ones."

"Choose one from many" has a similar meaning.

"Out of many, one" means that "Many were combined, to make one." (It is a translation of the Latin phrase e pluribus unum, which is the motto of the United States of America. Under the doctrine of dual sovereignty, the many continued to exist in parallel with the new federal government.)

"One from many" is ambiguous. It could mean "One chosen from many", or "Out of many, one."

The original poster's fourth through seventh questions can be answered affirmatively.

The idiom is "Do ____ from the comfort of your ___".

It's possible that your interpretation of what the phrase is trying to say is what's mixing you up.

The sentence is trying to say that people, given the option, would choose to work from home than in an office somewhere.

Your interpretation would imply that people work to make their home more comfortable... which is probably also true but not what the intention is.

So, examples of this phrase are:

Order now from the comfort of your couch!
Earn money from the comfort of your home!
Online learning from the comfort of your own home.
How to enjoy Burning Man from the comfort of your own home.

(note, these are often sales pitches or scams...)

As a note, "in" is definitely an option here as it is commonly used, too... but there is another idiom "work from home" which makes "from" the better option in my opinion.