Hey thanks for the tips, I was already aware of the story but I figured I already graduated so whatever. But better safe than sorry.

You shouldnt tell people that this map is based on a real school.
Why? https://www.theregister.co.uk/2007/05/03/student_counterstrike_map_texasschool/
Just change the name and remove the first picture which shows the map.

Furthermore try taking the screenshots with these three commands:
sv_cheats 1 (Enables the next two commands)
cl_drawhud 0 (Removes the Hud (Radar, Ammo Counter, HP and Armor))
r_drawviewmodel 0 (Removes the weapon modell)

Great map