뚜오 씨를 린꼬시장으로 뽑읍시다!
원 린꼬시장이 거액의 공금을 횡령한 것을 발견해서 뚜오 씨를 린꼬시장으로 뽑읍시다!
원 린꼬시장이 거액의 공금을 횡령하던 것을 발견해서 뚜오 씨를 린꼬시장으로 뽑읍시다!
How do I differentiate 한 and 하던?
Just like Roberto727 said. It's a time related difference.
노래한 사람 - person who sang
노래하던 사람 - person who was singing
던 is a combination of 더 grammar that expresses remembering something from the past and the (으)ㄴ past action grammar.
There is also 했던 that gives out the past perfect form. 노래했던 사람 - the person who had sung.
Depending on the context I believe it can also mean "used to".
I am not fluent nor native but I would say yes and yes.
Many times Koreans do add that 던 has a sense of repedition (even though you can also encounter it in phrases like "한국에서 3년 동안 살았던..." where the thought about living in Korea repeatedly in a course of 3 years makes less sense than "While I was living in Korea for 3 years...").
And because of that yes, if I had read this story I would expect more info about the embezzlement and how many times it has occured and I don't see any issue with why either one wouldn't work.
I wouldn't bet my own head though as I am also just another learner. If you want 100% certain answers I would say that the natives on Hinative or iTalki could offer better answers than my best guesses. On both platforms natives answer guestions from learners, correct sentences and give insight on the language.