Sorry for the late answer!
First of all, do you have an ios block in your pro file like the following?
ICON_DATA = ... QMAKE_BUNDLE_DATA += ICON_DATA
If yes you can remove them from your project file in case you’re using the latest V-Play libraries.
Regarding the icons:
We also already used the web tool you were linking to, iOS 8 icons should be just finde. We added a bunch of default icons to our wizards but you can safely remove unused icons after you updated your project file like mentioned above. We usually also use a small Photoshop script which generated the correct icons for us, if you’re using Photoshop too we can gladly share the script of course.
Regarding the Def*.png files:
These files are used as initial splash image on iOS-only. By default they are called “Default.png” (you can google for it), we however renamed them to Def.png as Qt bundles its own set of default launch images too, which would then conflict with our own.
Hope this answers your questions so far?