A message stating this should be shown in the kcontrol module, and the corresponding options should be greyed out.
I presume you mean a message and disabling similar to the KControl->System Administration->Login Manager->Appearance->Secure Attention Key check box?
Although I can write the pseudo logic, I doubt I can overcome my deficient C++ skills to detect those two conditions. With some coaching I would try but in the mean time I'll file a bug report.
I need examples of detecting text strings in non Trinity configuration files as well as how to detect that tdelibs was built with -DWITH_XCOMPOSITE=OFF.
By the way, enhancement request 1289: -DWITH_XCOMPOSITE=OFF, triggered my memory that a while back nothing I did to test compositing would work. Eventually I discovered the xorg.conf setting. Sure, my box and I created the xorg.conf --- years ago, which is why I did not remember. Still, my own experience demonstrates my point about confused users. :)
Darrell