For puzzles you need scripts.
For the hurt zone script do this.
change this:
:plrinzone:plraddhealth-=1
to this:
:activated=1,plrinzone:plraddhealth-=1.
Then create a hurt zone that is in a large area, and give the hurt zone that script.
Then set the switch's if used slot to the hurt zone's name
For a falling trap, create an anti-grav platform with this script:
:activated=1:destroy
Then name the lift fallingtrap, give it that script, and create a switch with the name of the anti-grav platform in the If Used slot.
Then put some items with physics force damage set to something high (over 1000) and put them ontop of the anti-grav platform.
Make sure the anti-grav platform is above the switch and VOILA.
Omigosh I'm a genius j/k
E.D.