  Studying the interplay between massive star formation and the interstellar
medium (ISM) is paramount to understand the evolution of galaxies. Radio
continuum (RC) emission serves as an extinction-free tracer of both massive
star formation and the energetic components of the interstellar medium. We
present a multi-band radio continuum survey of the local group galaxy M 33 down
to ~30 pc linear resolution observed with the Karl G. Jansky Very Large Array
(VLA). We calibrate the star-formation rate surface density and investigate the
impact of diffuse emission on this calibration using a structural
decomposition. Separating the thermal and nonthermal emission components, the
correlation between different phases of the interstellar medium and the impact
of massive star formation are also investigated. Radio sources with sizes <~
200 pc constitute about 36% (46%) of the total RC emission at 1.5 GHz (6.3 GHz)
in the inner 18' x 18' (or 4kpc x 4kpc) disk of M 33. The nonthermal spectral
index becomes flatter with increasing star-formation rate surface density,
indicating the escape of cosmic ray electrons {from their birth places}. The
magnetic field strength also increases with star-formation rate following a
bi-modal relation, indicating that the small-scale turbulent dynamo acts more
efficiently at higher luminosities and star-formation rates. Although the
correlations are tighter in star-forming regions, the nonthermal emission is
correlated also with the more quiescent molecular gas in the ISM. An almost
linear molecular star-formation law exists in M 33 when excluding diffuse
structures. Massive star formation amplifies the magnetic field and increases
the number of high-energy cosmic ray electrons, which can help the onset of
winds and outflows.
