FYI here's the command to perform the downgrade for the qt4 part :
sudo apt install qtchooser=47-gd2b7997-2 libqt4-dbus=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-dbus:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqtdbus4=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 qdbus=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqtdbus4:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqtcore4=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-xml=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqtcore4:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-xml:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqtgui4=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-opengl=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-network=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-network:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-opengl:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqtgui4:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-script=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-help=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-declarative=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-designer=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-scripttools=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-sql=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-sql-mysql=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-sql-sqlite=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-svg=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-test=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-xmlpatterns=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-xmlpatterns:i386=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 qt4-qtconfig=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-declarative-folderlistmodel=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-declarative-gestures=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-declarative-shaders=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-declarative-particles=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 qt4-qmlviewer=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-dev=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-dev-bin=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1 libqt4-qt3support=4:4.8.6+git64-g5dc8b2b+dfsg-3+deb8u1