Using latest KDE Plasma and KDE Framework on ArchLinux, I figured I have this files on my $HOME:

.fonts (fonts installed by Font Management) (should be here "$XDG_DATA_HOME"/fonts)
.kde4 (color-schemes, kdebugrc and kdeglobals) (should be here "$XDG_CONFIG_HOME")
.fonts.conf (don't know where should be this file)
.Xauthority (should be here "$XDG_RUNTIME_DIR"/Xauthority)
.gtkrc-2.0 (should be here "$XDG_CONFIG_HOME"/gtk-2.0/gtkrc)

I have tried exporting that files variables (the ones that have a global variable), but after deleting files, are created at next login.

Any suggestion?

While all kde 5 apps should be using the new XDG locations, I suspect things may still be saving to those locations for compatibility with older apps which haven't been updated to use the XDG standards.

I believe there was an environment variable for the .kde4 directory as some distros set that to just .kde instead (after they'd dropped support for KDE 3).

I think at the very least you may be able to set those up as links to the appropriate XDG locations; though proceed with caution if something is maintaining these for compatibility, lest it end up borking things when trying to resync the two paths.