Please try to see the code that Telescope uses for closing windows. May be you will notice something wrong there.

It would be interesting to check if XTerm and browser windows are actually closed normally by telescope, or telescope makes them to crash I think telescope might be sending incorrect or messages to closed windows and this might cause segfault or X errors in XTerm process

Actually, I havn't tested Telescope anywhere except N8x0. But some guys were successfully used it in mobile Ubuntu with LXDE as well.

If I recall correctly, X errors while closing windows were "normal", I mean they appeared on N8x0 too, but without any side effects.

Of cource, places where you have fixed syntax due to newer version of GCC need not to be decorated with defines.