I have come across one tacoma that had a weird buzzing noise from behind the glovebox. Yours may or may not be the same, however what I found was the actual label on the wire harness was flapping up agains something. Never would have expected it to be that loud! However there is also a TSB for the air intake rattling that could also be the culprit here. Try to shove a rag or something in where the airbox goes into the fender (there's a hole where it passes through) and see if the noise stops.
The steering wheel should be straight, assuming there isn't a lot of crown in the road, uneven road, wind, etc. If your alignment is out, this could also cause what is called bump steer, which basically when you go over bumps and stuff your wheel can kinda jerk around a little bit. The noise you're talking about is most likely the turn stops. There are little 'nubs' for lack of a better term that prevent you from turning your wheels past a certain point. These need to be lubricated from time to time, or if you hit a bump when you have the wheels turned near maximum, they make quite a racket.
Get a good alignment, tell them to lube the steering stops (they'll know what you're talking about) and that should take care of most of your issues. With the noise, your best bet (if you're out of warranty) is to have someone else drive the truck with you in the passenger seat, and just keep moving stuff, playing with stuff, etc until you either eliminate the noise, or change the noise. If you can change the noise, you know you're on the right track, and are not far from stopping it.
IF you're under warranty still, your 3/36 warranty will cover squeeks and rattles. You'll have to pay for the alignment, but you'll get your noises fixed for free :)