The issue is that your terminal is in bracketed paste mode, but doesn’t seem to support it properly. The issue was fixed in VTE, but xfce4-terminal is still using an old and unmaintained version of it.

You can try temporarily turning bracketed paste mode off by using:
***printf "\e[?2004l"***

***$ nslookup www.google.com
Server: 127.0.0.53
Address: 127.0.0.53#53

Non-authoritative answer:
Name: www.google.com
Address: 74.125.68.105
Name: www.google.com
Address: 74.125.68.99
Name: www.google.com
Address: 74.125.68.103
Name: www.google.com
Address: 74.125.68.147
Name: www.google.com
Address: 74.125.68.104
Name: www.google.com
Address: 74.125.68.106***

***$ ping 74.125.68.105
PING 74.125.68.105 (74.125.68.105) 56(84) bytes of data.
64 bytes from 74.125.68.105: icmp_seq=1 ttl=45 time=35.7 ms
64 bytes from 74.125.68.105: icmp_seq=2 ttl=45 time=35.2 ms
64 bytes from 74.125.68.105: icmp_seq=3 ttl=45 time=35.4 ms
64 bytes from 74.125.68.105: icmp_seq=4 ttl=45 time=35.6 ms
64 bytes from 74.125.68.105: icmp_seq=5 ttl=45 time=35.9 ms
64 bytes from 74.125.68.105: icmp_seq=6 ttl=45 time=35.2 ms
64 bytes from 74.125.68.105: icmp_seq=7 ttl=45 time=36.5 ms
64 bytes from 74.125.68.105: icmp_seq=8 ttl=45 time=35.3 ms
64 bytes from 74.125.68.105: icmp_seq=9 ttl=45 time=35.4 ms
64 bytes from 74.125.68.105: icmp_seq=10 ttl=45 time=35.6 ms
^C
--- 74.125.68.105 ping statistics ---
10 packets transmitted, 10 received, 0% packet loss, time 9013ms
rtt min/avg/max/mdev = 35.216/35.620/36.554/0.419 ms***

The following IP address ranges belong to Google:
***64.233.160.0 - 64.233.191.255
66.102.0.0 - 66.102.15.255
66.249.64.0 - 66.249.95.255
72.14.192.0 - 72.14.255.255
74.125.0.0 - 74.125.255.255
209.85.128.0 - 209.85.255.255
216.239.32.0 - 216.239.63.255***

Like many popular Web sites, Google utilizes multiple Internet servers to handle incoming requests to its Web site.

The kernel modules of the **nvidia** driver may still be present in your initramfs. Use **update-initramfs -u** to rebuild your initramfs file without the **nvidia** driver modules.

If it is a archlinux bootable iso, you don't have to do anything special. Just
***dd if=somefile.iso of=/dev/sdx***
where sdx is the block device like /dev/sda and not a partition like /dev/sda1.

This is possible as the iso already contains all that is needed. If you set some partition table, it will simply has no effect, as it will be overriden by dd, as anything else on the target device.

Edit: You sure have to unmout any partition on that device, as they will be overriden as described before.

Edit2: The same applies to the manjaro image, according to their wiki.

So this is how things are currently: PAM will just read /var/run/motd.dynamic and /etc/motd if it exists (paste from post)

/etc/motd – The classic, static file. Does not exist anymore in Ubuntu 16.04 LTS, not even as a symbolic link to /var/run/motd. If it is created, however its contents will be printed too.
/var/run/motd – This was used by Ubuntu’s first implementation. It is not used anymore. It is just ignored by PAM.
/var/run/motd.dynamic – This is what is shown on login currently. It is updated by /etc/init.d/motd at every boot. It is also updated by PAM by running the scripts in /etc/update-motd.d/, if they exist.
/etc/motd.tail – The Ubuntu package used to populate /etc/update-motd.d. One of them would cat the contents of this file so it was easy to add static content. That script does not exist in the package anymore, so the file does not have the intended effect.

The example from the post
***mkdir /etc/update-motd.d
rm -f /etc/motd # in Debian still exists
cat > /etc/update-motd.d/10logo < #!/bin/sh
echo
cat /etc/issue
EOF

cat > /etc/update-motd.d/20updates <<'EOF'
#!/bin/sh
echo
echo "uptime is $( uptime )"
echo "date is $( date )"
EOF

chmod a+x /etc/update-motd.d/***

If you run git init in a directory which isn’t already a git repository, removing .git will reverse all the effects of git init without any other side-effects.

In the Desktop Environment start the program "Terminal" or press ctrl-alt-F2 (F1 to F6 is normally possible).

Use usbtop, it gives a nice overview of what devices are using how much bandwidth:
***Bus ID 1 (USB bus number 1) To device From device
Device ID 1 : 0.00 kb/s 0.00 kb/s
Device ID 2 : 0.00 kb/s 0.00 kb/s
Bus ID 2 (USB bus number 2) To device From device
Device ID 1 : 0.00 kb/s 0.00 kb/s
Device ID 4 : 141.73 kb/s 13777.68 kb/s
Device ID 5 : 9.98 kb/s 11.24 kb/s
Device ID 6 : 0.00 kb/s 0.00 kb/s
Device ID 7 : 0.00 kb/s 0.00 kb/s
Device ID 8 : 141.71 kb/s 15257.26 kb/s***

I was not able to duplicate your issue. A login.ttl file with the following contents allowed me to successfully login to the desired ssh server (after placing the public key in the authorized_hosts file on the host).
***username = 'tester'
hostname = '192.168.100.1'
keyfile = 'c:\path\to\keyfile\id_rsa'

con = hostname
strconcat con ':22 /ssh2 /auth=publickey /user='
strconcat con username
strconcat con ' /keyfile='
strconcat con keyfile
connect con***

Other than LibreOffice, you could use an online conversion tool like Google docs to convert presentations from .pptx either directly or via a Firefox extension. There are other online conversion tools like Zamzar to convert the .pptx to a format that you can access on your machine; format choices include:

.html
.pdf
.odp
.png

Debian has a release maturity model, where Unstable, Sid, is where all the new stuff goes in. If it sticks, then Unstable becomes Testing, in which nothing can be added during testing. This typically lasts 1.5 - 2 years. If no problem at that point, Testing becomes the new Stable release.

Security updates are made to Stable first, then to Testing.

Debian Stable is notoriously stable, and notoriously behind the times, but very reliable for servers.

Ubuntu came along and said: we take Debian Unstable, make it more stable, add all the latest gadgets, drivers, etc, and release it.

Ubuntu then works at the security updates, package updates, etc, for their Ubuntu releases.

Note that I gladly use Ubuntu on the desktop, but I stick to Debian Stable for servers.

If you inform vim that you are using a black background (or otherwise dark theme) it will lighten up all the colors so they are readable:
***:set bg=dark***