kern_securelevel & X11

[unisal]

Hi all,
after my first experience with FreeBSD, I felt the necessity to
exchange some experience ( ... and actually ask to whom is
experienced).
I have installed, successfully, FreeBSD 11.0 CURRENT (standard
kernel) with MATE. All worked and IS working fine. 
My idea was to satisfy basic needs : print, scan, web life (... why
not all in the same time !). After same core-file  which didn't affect
the system, I tryed to follow a BSDGuides- Hardening FreeBSD (2005 ??!).
Almost all worked as expected but kern_securelevel in rc.conf gave me
same troubles. As I said "I am a beginner". A quick look in the
"main" book online in the main site and I understood my problem.
Inspite of the big red warning in the book, I opened a xterm and I
wrote : sysctl kern_securelevel=0.
I worked for a while and I decided to modify rc.conf: reboot and
trouble. Again modified rc.conf as was before: all fine.

with the idea to crash the system I send a command: sysctl
kern_securelevel=1.

I have been working for 5 hours (stressing as possible the system).
Has someone else had similar experience ? 
I wouldn't have expected any better.


I have a long experience with GNU/Linux DEBIAN and I am not afraid to
read; I really appreciate links or suggestions hoping not to bore no one.

Many Thanks to all in advance.

Sal.