This one: /home/linuxmce/.flickrfetchr.conf
didn't exist for me, but the other 2 did.
Did you get it working for the wife? As I said, I didn't like that it only pulls public photos, so I turned that off and just put my pictures on the NAS and added the device to the core as a windows share.... added the pictures as a screensaver for MD.... and it worked great, for the most part.
My pictures are not 1024x768- some are 3000 something by 2000 something (I think). What's odd is that sometimes the pictures showed up great on the screen, and sometimes the imaged was zoomed in on one of the sides of the image. And, what's more, is that screen would sometimes get stuck on one picture- the picture was different everytime- seemed to be a random thing (sometimes 15 min, sometimes 5, etc). By skipping to the next song it usually restarted the pictures.