Shooting into Zones with Survivors
"Only misses on Attack rolls of '1' hit Survivors standing in the target Zone."
Exterior Zone Weapon Limitation
"Bullet-based weapons are allowed to fire in both interior and exterior zones."
"Searching by Soldiers AND Civilians can ONLY be performed in the red security rooms."
One option would be just to treat the red rooms like every other room and anyone can search anywhere. I do, however, think acquiring items is a bit too easy in this game and since the game gets a little easier with the previous two house rules, I figured making it harder might be something fun to try. So...both Civilians and Soldiers can ONLY search in red rooms. When using the walls/floors I made, the security rooms are signified by the red 'item vending machines' so it is somewhat thematic as all sorts of good stuff can be stored there and they are fairly easily accessible. This may totally not work out in some scenarios and is sort of a prototype house rule that I'm not sure I'll keep going forward.
The exception to this house rule is that any character with the Free Search Action ability may use that action to search in any type of room. This allows the 'search-oriented' characters to not take a big hit on their primary ability.
Bot/Turret Activation Limit
"Each Bot and Turret may only be activated a total of 4 times per Player Phase via the remote."
No more 'passing the remote'. The bots and turrets are fairly powerful assets and can easily be abused by all the characters sitting in a room and passing the remote around giving the bot a dozen or more actions in a given turn. The Character's actions can be thought of as semi-simultaneous and serializing the actions by passing the remote around while the Characters down the line just sit there and 'wait' just kind of breaks the mental picture and intent of the game.
Note that this only applies to the remote control token and not to Characters with the "Remote Control: Bot/Turret" skill nor Characters standing in the same zone as the Bot/Turret. 'Free' machine actions and 'extra activations' (such as from Born Leader) do not apply to the activation limit and can always be used to activate a machine.