  We unravel stationary states in the form of dark soliton stripes, bubbles,
and kinks embedded in a two-dimensional droplet-bearing setting emulated by an
extended Gross-Pitaevskii approach. The existence of these configurations is
corroborated through an effectively reduced potential picture demonstrating
their concrete parametric regions of existence. The excitation spectra of such
configurations are analyzed within the Bogoliubov-de-Gennes framework exposing
the destabilization of dark soliton stripes and bubbles, while confirming the
stability of droplets, and importantly unveiling spectral stability of the kink
against transverse excitations. Additionally, a variational approach is
constructed providing access to the transverse stability analysis of the dark
soliton stripe for arbitrary chemical potentials and widths of the structure.
This is subsequently compared with the stability analysis outcome demonstrating
very good agreement at small wavenumbers. Dynamical destabilization of dark
soliton stripes via the snake instability is showcased, while bubbles are found
to feature both a splitting into a gray soliton pair and a transverse
instability thereof. These results shed light on unexplored stability and
instability properties of nonlinear excitations in environments featuring a
competition of mean-field repulsion and beyond-mean-field attraction that can
be probed by state-of-the-art experiments.
