Here are some ideas that can help you. One master locks are some of the hardest locks to pick so start with that. Yes a central light control would be great. Here is what I do. Take some time and lay in bed, get up grab you gun and do a sweep of where you are living now. Think about what you like about it and what you don't. My buddy and I have been thinking about starting a class that teaches people how to single clear a house as well as the theories behind it. We trained a bunch of our friends after a break in in their neighborhood, the next time it was one of them and the as they made their way to the stairs the robber left with out a shot because they were in a good position and armed and hard to see.
Things I like in the house.
Single stairway up to the next floor.
Large window in the living room, leaving the curtains open. Shed the light on the robber.
Central light switch, even some flood lights above the stairs to mask your position coming to the top of the stairs.
Sleep with bedroom doors open. You have to figure if they are opening it, it is to late to do anything. If it is open you have the jump on them.
There are a lot of things you can do, just sit down and think about it.
"The only breath that matters is the one you take after the other person isn't breathing. That is the only breathing that matters in a tactical situation. Train like you fight, in battle you will be breathing rapidly and shooting, not holding your breath." Johnny Rimer SO1 (Ret.)