CentOS

You don't. For a start you need to read the RHEL backporting web page https://access.redhat.com/security/updates/backporting to understand how it works. RH backport fixes to their 2.4.6 version so... [root@here ~]# rpm -q --changelog httpd | grep -iE "CVE-2017-7679|CVE-2016-2161|CVE-2019-10098|CVE-2...

Yes, you are counting wrong. 4 cores, 8 threads is 8 cpus in top, not 12. You don't add them together.

Yes, MS broke it, complain to them. They have built the latest version to require a newer glibc than we ship. The chances of that changing are nil so either MS fix it or it stays broken. In the meantime you will need to yum downgrade skypeforlinux-8.56.0.103-1.x86_64 which is the last working version.

Your ctrl key is stuck down. Press and release them both to make sure you get the right one.

Most likely you are missing the glibc-langpack-$locale for your locale. Install it, try again.

Show us the current situation:

df -h
fdisk -lu /dev/sd[a-z]

and how you'd like it to be.

There is no "recovery" from this. You backup your data and you reinstall the system. You have no idea how many ways they have backdoored your system nor in how many ways they are siphoning off data from the system for later use. You will never be able to trust this system again.

Please raise a bug on bugs.centos.org to report this though as far as I am aware, the security profile is intentionally unsupported on CentOS.

And how much RAM does this machine have? The minimum required is 2GB.

If you added those lines as-is with the # sign at the start, they are comments and do nothing.