Survival Horror: Exploration and NPCs

I'm in the very early design stages for a survival horror game (it's not zombies!).

One of the major mechanics will be "exploration" of some sort. I say "exploration" because it's more of a run into unknown territory and see what's there sort of thing.

I have a number of possible ideas as to how this may work, and wanted to get thoughts on the options and possibly see if there are similar mechanics in other games that I could look to for ideas.

The first idea is to have the entire map covered in tiles, that would flip over when you're in sight range. The tiles would have a set outcome, from an enemy appearing, an ally, an environmental hazard, nothing, etc.

The second would be to have these tiles, but instead of them having a set outcome, they would have more of a "danger level", which would be resolved by either drawing a card from the appropriate deck or rolling on the appropriate table.

Another idea is to simply have the player draw an "event" card (at the beginning or end of their turn, or both?), which determines what pops up nearby.

I'm sure there are other possible ways to go about this, but those are my thoughts at the moment.

The other issue is how to handle the NPC enemies that pop up. I'm not interested in having all the bad guys being played by a player, I want the game to work out more as a cooperative storytelling/survival experience.

The biggest issue would be handling their movement and "patrols". The characters controlled by the players are extremely weak and vulnerable compared to the enemies, and so the focus is more on avoiding and hiding than confronting them in combat.

One idea I had was to have each type of enemy have their own action deck, which you would draw a card from to determine their action that turn. Cards would be simple things like "Stand still", "Move forward two", "Patrol zone", "Search", "Turn", "Move On", etc. It would also be possible to simply have an action table that you would roll on, and as much as that simplifies components I don't really like the idea of the alien actions having independent probability.

What games out there have good NPC AI mechanics as far as patrolling/searching for the players?

Thanks!