You are going to have to clarify what you did a bit for a geezer like me. You said you downloaded 4.5 first. Did you install it? If so, where? Your C drive or G? Then you used the new Install Manager to download and install 4.6 and pointed it at your G drive. From what you described, I’m not sure everything installed on G correctly. The DAZ Studio installer creates a folder named DAZ 3D (this would be in C:\Program Files in a default installation) with two subfolders: DAZStudio4 into which almost everything, both the application and content, are installed; and a folder called Content Management Service that contains the content management application, its database and supporting files. Long breath ...
Okay, so first of all, if you did install 4.5, and it was not uninstalled during the installation of 4.6, then one of them needs to go. You can’t have both installed on the same system concurrently.
As for your original question, I assume you are asking where your content (models, etc.) are? Well, they are normally stored in bits and pieces in those various folders you mentioned. All Poser format files will be in folders under that Runtime folder, while DAZ Studio specific files will be in some of those others. If you are expecting to see folders labelled with the names of each specific model, or character, the content is not exactly organized that way, whether it is DAZ Studio or Poser format. If you take the base model Victoria as an example, that is not a single file, but a series of different files, each containing a different type of data relating to the model stored in folders that contain all data of that type. Generally, it is up to the application (program) to locate all of this and to present it to you through the program’s interface. That way, you really don’t need to go looking for it on the hard drive, as the software does that for you. Have you opened the application and checked for the installed content there?
Lastly, have you installed any other content beyond that which ships with DAZ Studio?