@Marietto

I wish you good luck in your endeavor.

I do not have as much experience and skill as some of
your other respondees. What I have to offer is a counsel
of caution.

My experience with removing things from a robust working
system, such as Knoppix, is such as to make me wary of
removing certain functions I deem to be superfluous
to my needs and taste.

Very often in removing supposedly superfluous programs,
I end up with an unworkable system. Not only unworkable,
but I don't know what to 'put back'. This is usually the
result of the removal of a program previousy shared by
the program removed and the remaining system. This is
a self-inflicted case of 'dependency hell'.

If you keep good records and images you can survive this
difficulty, but I am not so well organized as all that.

I had in mind you might be better off a with non-graphic
single-user linux system. There used to be a number of
these, but now I can't readily find any. Live CD's for
the purpose of disaster recovery or forensics or security
purposes used to be very common.

It looks like this genre may have been superseded now
by lightweight graphic systems, such as lxde, xfce and
others. Perhaps the baggage in these systems is much
lighter now than previously, with not so much overhead
above the command-line essentials.

Avenues apart from downsizing Knoppix, might include
building up from scratch, ala linux-from-scratch,
and/or using neat bare-bones linux-building blocks
like busybox.

I'm sure you'll get to Rome, one way or another or both.