I’ve installed 15 for a while, just noticed that one of the software on overview is not available which is Qt.
Changes in an overview (excerpt):
Kernel 3.16.0.30~40
KDE Plasma 5.2
KDE Frameworks 5.7
Qt5.4
Firefox 35.0.1
Thunderbird 31.4.0
VLC 2.2.0
LibreOffice 4.4
Krita & Karbon 2.8.5
Gimp 2.8.10
Pidgin 2.10.9
and much more…
The linux kernel update from a few weeks ago mean that I have to select advanced boot options to select the previous kernel. The other kernel kept crashing
To 1) I am not sure what you mean. Qt5.4 is installed otherwise plasma 5 and the rest could not work.
To 2) If the new kernel isn’t working for you just remove it with muon or synaptic.
An error report to upstream ubuntu would be also a nice way to let them know that there is something wrong with their kernel.