  Context: NGC 7538 IRS 1-3 is a high-mass star-forming cluster with several
detected dust cores, infrared sources, (ultra)compact H$_{\rm II}$ regions,
molecular outflows, and masers. In such a complex environment, important
interactions and feedback among the embedded objects are expected to play a
major role in the evolution of the region. Aims: We study the dust, kinematic,
and polarimetric properties of the NGC 7538 IRS 1-3 region to investigate the
role of the different forces interplaying in the formation and evolution of
high-mass star-forming clusters. Methods: We perform SMA high angular
resolution observations at 880 $\mu$m with the compact configuration. We
develop the RATPACKS code to generate synthetic velocity cubes from models of
choice to be compared to the observational data. We develop the "mass balance"
analysis to quantify the stability against gravitational collapse accounting
for all the energetics at core scales. Results: We detect 14 dust cores from
3.5 $M_{\odot}$ to 37 $M_{\odot}$ arranged in two larger scale structures: a
central bar and a filamentary spiral arm. The spiral arm presents large scale
velocity gradients in H$^{13}$CO$^+$ 4-3 and C$^{17}$O 3-2, and magnetic field
segments well aligned to the dust main axis. The velocity gradient is well
reproduced by a spiral arm expanding at 9 km s$^{-1}$ with respect to the
central core MM1, which is known to power a large precessing outflow. The
energy of the outflow is comparable with the spiral arm kinetic energy, which
is dominant over gravitational and magnetic energies. In addition, the
dynamical ages of the outflow and spiral arm are comparable. ... (Full abstract
in the pdf version)
