Error while installing updates 3.0

[technomancer]

I have installed LL 3.0 and have an update error as well.

Code:

apt-get update
[sudo] password for technomancer:
Hit:1 http://repo.steampowered.com/steam precise InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease                     
Hit:3 http://repo.linuxliteos.com/linuxlite citrine InRelease                 
Hit:6 http://ppa.launchpad.net/nemh/systemback/ubuntu xenial InRelease         
Hit:7 http://archive.canonical.com xenial InRelease                           
Hit:8 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease           
Err:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease                     
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
Get:4 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [94.5 kB]   
Get:5 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB]   
Hit:9 http://ppa.launchpad.net/otto-kesselgulasch/gimp/ubuntu xenial InRelease
Err:3 http://repo.linuxliteos.com/linuxlite citrine InRelease                 
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 22AAEA0A86A02625
Hit:10 http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu xenial InRelease       
Err:7 http://archive.canonical.com xenial InRelease                           
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
Err:8 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
Err:4 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
Err:5 http://security.ubuntu.com/ubuntu xenial-security InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
Fetched 189 kB in 1s (161 kB/s)
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://us.archive.ubuntu.com/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repo.linuxliteos.com/linuxlite citrine InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 22AAEA0A86A02625
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.canonical.com xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://security.ubuntu.com/ubuntu xenial-security InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: Failed to fetch http://archive.canonical.com/dists/xenial/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5  NO_PUBKEY 3B4FE6ACC0B21F32
W: Failed to fetch http://repo.linuxliteos.com/linuxlite/dists/citrine/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 22AAEA0A86A02625
W: Some index files failed to download. They have been ignored, or old ones used instead.

Here is my /etc/apt/sources.list file contents

Code:

# deb http://us.archive.ubuntu.com/ubuntu/ xenial main restricted

# deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
# deb http://security.ubuntu.com/ubuntu xenial-security main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://us.archive.ubuntu.com/ubuntu/ xenial main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://us.archive.ubuntu.com/ubuntu/ xenial universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial universe
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://us.archive.ubuntu.com/ubuntu/ xenial multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial multiverse
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu xenial partner
# deb-src http://archive.canonical.com/ubuntu xenial partner

deb http://security.ubuntu.com/ubuntu xenial-security main restricted
# deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted
deb http://security.ubuntu.com/ubuntu xenial-security universe
# deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb http://security.ubuntu.com/ubuntu xenial-security multiverse
# deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
deb http://archive.canonical.com/ xenial partner
# deb-src http://archive.canonical.com/ xenial partner

Here is the llupdates.log as well

Code:

Reading package lists...
Building dependency tree...
Reading state information...
Calculating upgrade...
The following packages will be upgraded:
  libmysqlclient20 libmysqlclient20:i386 linux-firmware lshw mysql-common
5 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 34.4 MB of archives.
After this operation, 1,092 kB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  lshw mysql-common libmysqlclient20:i386 libmysqlclient20 linux-firmware
E: There were unauthenticated packages and -y was used without --allow-unauthenticated

Also my theme and icons change to the following screen-shot after 10 seconds for some reason. Looks like a default ?