i see you're using more than one instance of fluidsynth-dssi.
as a matter of fact the current latest released version (v1.0.0, since 2009) of the fluidsynth-dssi plugin has a crash bug that serious manifests when you instantiate more than one instance of it; this bug has been corrected upstream and should be silent now on git head (ca. 2012); unfortunately most if not all distros, including opensuse, still deliver the old bugged version.
i believe this is the root of your troubles with fluidsynth-dssi, there might be others but this is one i know for sure. and this might relate to both of your questions above.
you have some couple of options here then:
avoid having more than one instance of fluidsynth-dssi plugin in any one time; if you're loading the same sf2 file on each MIDI track for instance, consider to make it a single instance inserted on an output MIDI bus instead;
un-install current package, clone and build and install from upstream git repo and try and test whether the same troubles still prevail every so often.
i see you're using more than one instance of fluidsynth-dssi.
as a matter of fact the current latest released version (v1.0.0, since 2009) of the fluidsynth-dssi plugin has a crash bug that serious manifests when you instantiate more than one instance of it; this bug has been corrected upstream and should be silent now on git head (ca. 2012); unfortunately most if not all distros, including opensuse, still deliver the old bugged version.
i believe this is the root of your troubles with fluidsynth-dssi, there might be others but this is one i know for sure. and this might relate to both of your questions above.
you have some couple of options here then:
take both and all will be even finer, i hope ;)
hth.
cheers