So, to make Skype, VLC (and all other QT apps) use the default Awaita theme (or the theme you want) on Opensuse Gnome, edit the following file and type the theme you want (in my case, I make all the apps use the black DMZ / Adwaita cursor theme):
# nano /etc/sysconfig/windowmanagerFind line
Change DMZ to DMZ-AA (or for the name of your theme of choice). Save changes.
Logout. Login. Now you see the cursor you want in Skype and other QT apps.