Further detail that may help diagnosis.
I STILL get the gtk errors EVEN WHEN IT WORKS. (in the past I habitually ran it remotely with "beersmith2 >/dev/null 2>&1 &" command line, so never saw the gtk errors until I went looking for output/errors) But after those errors one of two things comes next from my perspective - either the window asking about registration opens, or Beersmith crashes with a core dump, depending on whether it's registered.
When run locally the splash window appears empty for a second or three, then less than one second after the name/logo appears within that window the window closes followed a few seconds later by the registration window or the main window - remotely, the empty window appears and immediately closes followed by the gtk errors. Then it thinks a moment, and the registration window opens or the segfault message appears and it's over.
If I replace opts.xml and .bsopts from a backup of the un-activated .beersmith2 folder it reverts to working again, simply asking each time about registration. Once registered it will always crash before opening the main window when run remotely, though it still runs locally on that machine.
So it really looks like there's something different taking place when the reg window opens that prevents the full crash from occurring. And the GTK errors are triggered apparently by the Beersmith2 splash, and may or may not directly relate to the crash.
j