The readmes do not, in general, overwrite each other as they have distinct names. The paths are in dzinstall.ini - the location of that depends on the vintage of the installer, so you can have different paths cropping up - and different paths for Poser and DS format content - but the path should be remembered from installer to installer so you shouldn't have to correct more than a few times. Very old installers don't use a stored path at all. The desktop shortcut is to the DAZ store - if you don't want to keep clicking No just leave it on, then delete the single shortcut from your desktop when done.