Answer:
The first one, there are lots of challenges that computer forensic scientists face everyday on their jobs, some of them are, the rise of antiforensics techniques, data analysis, and the development of standards. These things are very hard because, once there is a problem, these scientists need to search for information, and this information might be very new to them, and they need to study it and analyse it very quickly and wisely in a way that don't affect the whole investigation negatively.
The second one, some skills that these scientists need to have are, the capability of analysing a very high amount of information in a very short period of time, communication skills, and the attention to every single detail on their work. I don't think I possess all these skills, but it's not impossible to reach them, it's a matter of practice and study.
These skills are not easily achievable, you need to focus a lot to develop them, and this demands a very good amount of time, something that's very hard to have on these days.