(1). gtklib is a simple pascal string constant. It probably contains just "GTK2" meaning that libgtk2.so is sought.
The application wouldn't start if the dependency wasn't satisfied, so that is not the problem.
What causes the problem is not clear. Could be something in the build of GTK for that platform that is either buggy or triggers a bug, but that is hard to find out.
GTK is notoriously buggy and versioned, so the same program can behave differently on different distro/versions.
(2) Well there is QT of course, and maybe a hope that the GTK situation improves. If both fail, there is still Wine.