What is required for 3D in QtQuick 2?
What is required to create a 3D scene with QML. AFAIK "Qt3D":http://doc-snapshot.qt-project.org/qt3d-1.0/qt3d-building.html was included in Qt5 so it should be accessible somehow.
What is the required module name?
@import QtQuick.Qt3D 1.0@
No, Qt 3D was not ready for the release, so it was excluded from Qt 5.0.0. Hopefully, it will be back in Qt 5.1.0.
The full list of Qt 5.0.0 modules is here: http://blog.qt.digia.com/blog/2012/11/13/qt-5-0-beta-2-is-out/ (although, they forgot to mention Qt Multimedia Widgets!)
How can I use Qt3D with Qt5 then? How do I install it?
I'm not sure, sorry. But apparently, Qt 3D is incomplete and not fully usable: http://lists.qt-project.org/pipermail/interest/2012-December/004930.html
(You can probably sign up at the mailing list and ask there -- someone might be able to tell you how to install it)