to the 1st question: Yes, of course (it's in the guide). However, there's a whole lot of services unused, many more than I would expect:
lvmetad [ stopped ]
mit-krb5kdc [ stopped ]
samba [ stopped ]
udev-settle [ stopped ]
brltty [ stopped ]
net.lo [ stopped ]
bootlogd [ stopped ]
dnsmasq [ stopped ]
busybox-watchdog [ stopped ]
cupsd [ stopped ]
net-online [ stopped ]
apache2 [ stopped ]
cups-browsed [ stopped ]
lvm [ stopped ]
mdraid [ stopped ]
openrc-settingsd [ started ]
device-mapper [ stopped ]
osclock [ stopped ]
consolefont [ stopped ]
nvidia-persistenced [ stopped ]
pydoc-2.7 [ stopped ]
git-daemon [ stopped ]
dhcpcd [ stopped ]
boltd [ stopped ]
pwcheck [ stopped ]
runsvdir [ stopped ]
dmcrypt [ stopped ]
iptables [ stopped ]
swclock [ stopped ]
pciparm [ stopped ]
ip6tables [ stopped ]
saslauthd [ stopped ]
busybox-ntpd [ stopped ]
gpm [ stopped ]
xdm-setup [ stopped ]
s6-svscan [ stopped ]
mit-krb5kadmind [ stopped ]
numlock [ stopped ]
udev-postmount [ stopped ]
mit-krb5kpropd [ stopped ]
xdm [ stopped ]
avahi-dnsconfd [ stopped ]
pydoc-3.7 [ stopped ]
rsyncd [ stopped ]
fuse [ stopped ]
mdadm [ stopped ]
slapd [ stopped ]
dmeventd [ stopped ]
lvm-monitoring [ stopped ]
agetty [ stopped ]
wpa_supplicant [ stopped ]
nvidia-smi [ stopped ]
To the 2nd question:
SESSION UID USER SEAT TTY
1 0 root seat0 tty1
1 sessions listed.
Moreover, the output of emerge -auND @world show that some NVIDIA-modules need to be compiled, whereas my system is AMD based. Even in the above listing you see a few nvidia-services. While my profile is:
=== Enabled Profiles: ===
arch: x86-64bit
build: current
subarch: amd64-zen
flavor: desktop
mix-ins: gnome
mix-ins: gfxcard-amdgpu
=== Python kit: ===
branch: 3.7-release
=== All inherited flavor from desktop flavor: ===
workstation (from desktop flavor)
core (from workstation flavor)
minimal (from core flavor)
=== All inherited mix-ins from desktop flavor: ===
X (from workstation flavor)
audio (from workstation flavor)
dvd (from workstation flavor)
media (from workstation flavor)
mediadevice-audio-consumer (from media mix-in)
mediadevice-base (from mediadevice-audio-consumer mix-in)
mediadevice-video-consumer (from media mix-in)
mediadevice-base (from mediadevice-video-consumer mix-in)
mediaformat-audio-common (from media mix-in)
mediaformat-gfx-common (from media mix-in)
mediaformat-video-common (from media mix-in)
console-extras (from workstation flavor)
print (from desktop flavor)
=== All inherited flavor from gnome mix-ins: ===
desktop (from gnome-kit:gnome mix-in)
workstation (from desktop flavor)
core (from workstation flavor)
minimal (from core flavor)
=== All inherited mix-ins from gnome mix-ins: ===
gnome-kit:gnome (from gnome mix-in)
X (from workstation flavor)
audio (from workstation flavor)
dvd (from workstation flavor)
media (from workstation flavor)
mediadevice-audio-consumer (from media mix-in)
mediadevice-base (from mediadevice-audio-consumer mix-in)
mediadevice-video-consumer (from media mix-in)
mediadevice-base (from mediadevice-video-consumer mix-in)
mediaformat-audio-common (from media mix-in)
mediaformat-gfx-common (from media mix-in)
mediaformat-video-common (from media mix-in)
console-extras (from workstation flavor)
print (from desktop flavor)
=== All inherited mix-ins from gfxcard-amdgpu mix-ins: ===
core-gl-kit:gfxcard-amdgpu (from gfxcard-amdgpu mix-in)
Strange...