Okay, I've seen a lot of posts say that the only way to get into the T'rang restricted area is to kill the T'rang.And this simply is not true. It takes a bit of patience, but it is very easy to repeatedly go into and through the "restricted areas" without laying a finger on the T'rang or making them hostile.
I read about it in a post in this forum a while back, but it doesn't seem to have been passed along enough. The basic idea is that you enter combat mode yourself, before going into the restricted area. I usually walk until one of the guys says 'Stand back!' Then click on the battle icon, select run, and okay, and then run past them. It might take a try or to at first, but it's very easy to run past them. By the time your run bar runs out and you exit combat, you should be past the T'rang.
One of the restricted areas is a bit trickier, where you have to enter in the 3-digit code to open the door (after turning off the gas). But the basic idea is the same, using false combat mode. Once inside this area, you can find a weapon in the very center, surrounded by a group of T'rang. Best strategy? Enter false combat mode, pick up the item DURING combat mode, then run away as fast as posible. These strategies have always worked for me.
Alternatively, you can try to camp until you engage in a battle near the T'rang that will cause them to run away. This in my opinion is much more of a hassle, but is still possible.
IMO, Sirtech planned it this way all along. Turning on/off the gas is not an issue if you've defeated the T'rang. But if you try the false combat method, forgetting to turn off the gas will force you into combat. So why include it, unless they planned on you using the false combat mode?
Really, this is not any trickier than making characters unconscious to enter areas, and Sirtech knew about that quite well, as it even has some of them comment that "You must've gotten me unconscious..."
Anyway, I just wanted to pass that along, in case some maniac gamers out there wanted to get and do everything, without upsetting the T'rang.