Maybe that could be related to the window manager. On my distro, you can change it in Paramaters > Desktop Parameters. It shows a list of window managers.
It's certainly something worth considering. However the first thing is to reach consensus on whether
* Lazarus etc. is locking up and has to be killed using a window manager facility.
* Lazarus etc. is locking up and taking the window manager with it.
* Lazarus etc. is breaking the kernel (unlikely, and a kernel developer's problem).
An obvious part of the problem is that the modern desktop environment is rather more than the traditional window manager. It /used/ to be possible to change the window manager on the fly since basically all it was doing was providing the "furniture" around application windows, i.e. title bar etc. These days the window manager is basically chosen by the display manager (which handles login etc.), and includes much more that the traditional window manager.
Remember that if you change the desktop environment (window manager etc.) you might not have a convenient GUI option to change it back. Going through my historical notes I think the selection is stored in ~/.dmrc but that might actually redirect to another configuration file stored by the display manager. I suggest that anybody tinkering with this work that detail out before starting, or at the very least make sure that the display manager login screen has the option of selecting the window manager (desktop environment).
Another fair question is whether it's widget-set specific, i.e. are the apps which are failing built for gtk3 rather than gtk2 etc.
I'm not in the loop for trying to fix this, but those are basic support level questions that the people with the problem need to consider.
MarkMLl