  Spectroscopic data are necessary to break degeneracies in asteroseismic
modelling of the interior structure in high- and intermediate-mass stars. We
derive precise photospheric stellar parameters for a sample of 166 B-type stars
with TESS light curves, suitable for detailed asteroseismic studies, through a
homogeneous spectroscopic analysis. The variability types of these stars are
classified based on all currently available TESS sectors. We obtained
high-resolution spectra for all 166 targets with the FEROS spectrograph in the
context of a large program. The Least-Squares Deconvolution method is employed
to investigate spectral line profile variability and to detect binary systems.
We identify 26 spectroscopic double-lined binaries; the remainder of the sample
are 42 supergiants in the LMC galaxy and 98 Galactic stars. The spectra of the
Galactic stars are analysed with the zeta-Payne, a machine learning-based
spectrum analysis algorithm. We determine the five main surface parameters with
average formal precisions of 70 K (Teff), 0.03 dex (logg), 0.07 dex ([M/H]), 8
km/s (vsini), and 0.7 km/s (vmicro). The average internal uncertainties we find
for FEROS spectra with our spectrum analysis method are 430 K (Teff), 0.12 dex
(logg), 0.13 dex ([M/H]), 12 km/s (vsini), and 2 km/s (vmicro). We find
spectroscopic evidence that eight of the 98 Galactic targets are fast rotating
g-mode pulsators occurring in between the slowly pulsating B (SPB) stars and
delta Scuti instability strips. The g-mode frequencies of these pulsators are
shifted to relatively high frequency values due to their rotation. Their
apparently too low Teff relative to the SPB instability region can in most
cases be explained by the gravity darkening effect. We also discover 13 new
HgMn stars of which only one is found in a spectroscopic binary, resulting in a
biased and therefore unreliable low binary rate of only 8%.
