важное is important, while главное is the main thing. Am I right here? please comment.
Incorrect! "Main" is not equal "important". That is evidently.
Money is not main thing, but they are important.
As my grandfather used to say: "The important thing is the AMOUNT of money" XD
"Главное" here is sort of an adjective that became a noun. It means "important thing".
¨главное¨ is just and adjective that follows ¨ что-то¨ which is omitted but requires a neuter adjective; деньги не (что-то) главное.
I translated "....AN important thing" instead of ".....THE important thing" and was marked wrong, what is the difference?
I put money is not the important thing last time and it was corrected to money is not the most important thing. So this time i put it that way and it corrected me to my oruginal translation. Duo can have it both ways i suppose, and i am wrong no matter how i translate this sentence.