Non linear fps zombie survival game

I am new to torque and still learning programming, but here is my idea of a game i have wanted to make for a very long time although some details i'm not dead set on yet, just interested in some opinions.

The setting is a large city in which a massive zombie outbreak has just occured. To start out you will choose your name, your father, mother, brother, sister, girlfriend and best friends name which will be used for npc's
you will want to find and protect throughout the game to help give some direction in the game.

Other then that you will roam through the city trying to stay alive finding food, water and weapons and avoiding being eatten and finding other survivors along the way that will either help you, slow you down or try to kill you and take any supplies you have.

As far as the map goes i want to have a good size map for plenty of exploring while the edges will be restricted by military barricades and soldiers who will shoot if you approach close enough trying to keep the infected quarintined off from the rest of the world, which will be part of the games goal to figure out a way to escape.

For inventory i want to go very realistic I.E. you can't carry an assault rifle in your pocket.
I had an idea to use your clothing and jacket along with finding a backpack. If you have ever played parasite eve 2 for PSX it will be very much like that.

I want to include a way to barricade yourself inside buildings, for example you would run into an apartment building shut and lock the door, then pile furniture and such to hold it shut, board up the windows and hope it holds the zombies at bay. My thoughts were to have a weight value for the doors and windows which the zombies have their own value and as they pile up on the door their weight adds up together until it is over the doors limit and it caves in, to counter as you pile things in front of the door it adds to the doors limit and reinforces it.

I also had an idea of a population counter to try to help the frame rate while still keeping the feeling tense as zombies keep coming and coming.
The way it works in my head is the map is divided into sections with the number of zombies in that section which basicly keeps a number of non-spawned zombies. The player has an invisible circle around him, as he kills zombies more will spawn at the edge of the circle and creep in on him. Also as he makes more noise and draws attention to himself the number of zombies from surrounding sections will migrate to the section he is in adding more and more enemies.

I have alot more specific ideas in mind, i won't post them all right now just wanting some feedback.

thanks, Matt