With regards to the skills shat kind of skills are we allowed to choose? Can it be something fairly normal such as being a computer genius or having and eidetic memory, or can be something fairly supernatural like the ability to see and hear things that aren't there, and maybe something even more superhuman?

As for the background is it necessary to have had a life that is involved in criminal investigations? What I mean to say is that are we allowed to make a character that has not formal or any experience in criminal investigations, but have had experiences dealing with the unusual in an investigative way? Going beyond that is it necessary that their history is that on the side of criminal investigators or are we allowed to have a character that was on the side of making crimes, unusual or otherwise, that needed investigation?