I have read a lot of information saying that 6,8,12th house moon placements are extremely difficult to have but I’m curious to know more depth on it. Which signs in those houses could make it harder? And also aspects? How does having a day chart vs a night chart change its expression?

If you don’t know someone’s birth time, how do you work out their ascendant/rising? since it’s such an important placement it’s important not to get wrong.