Some good news. The healing and freezing trick work like a charm. The numbers have to be pretty big for it to work correctly but here goes.
A freeze damage of 100HP will strip 20 units of power from the suit every .5 seconds. Any higher than this and it will instakill any player who passes through with no armour at all, regardless of how strong the countering heal trigger is. Unfortunately, if the player enters these triggers with less than 100% health, this will also kill them.
The solution I have come up with is that the player will enter a strerilisation chamber on each floor. This will seal them in for 3 seconds, strip their weapons, regen their health (at a power of 100000 so this will be instant) and then sap their armour. That way they will always be at 100% HP when the freeze hits. Then the door opens and the triggers are killed (stops players back tracking to get more health if your level is tough)
This does of course mean I will need more room in the stairwell... Not a great deal, just a square space beyond your blockade which can be accessed once your floor is done with. Editing options there are getting limited in the stairwell huh?