I see someone else pretty much covered a lot of this.
I refuse to use HDRI's because they are very limited and have always increased my render time. They became too much of a pain in the ass. Not that this helps you at all, just sharing my personal gripe about the things.
I did want to add that in your Daz content browser, you can right click and do "Browse to File Location" to bring up the item in the directory it's stored in. I do this to reorganize all my assets because I get tired of having to remember which creator created what to find this or that. Not sure if that's what you meant, but I hope this helps. Cheers mate!
Oh, also, AMAZING PIC!