Last question first...no, if you don't have the original source and only have the published zip files, I don't think you can successfully edit it in the files. Each page in the zip represents a page in the module plus a course index and several other bits that make it work. In theory, you could find the page that submits the variable and replace it but I wouldn't want to try that.
As for the first...I don't use Articulate but I understand the settings in it are different than those in the authoring software I use. I know there are several forums on here that talk about storyline--you might check them and the Articulate community is really terrific, very supportive and easy to use.