1) Do performance chips actually add 30+ horsepower and 8+ mpg?
IMHO, not an expert. Things that add HP don't usually increase mpg. I'd buy one if it really existed. Superchargers, turbos (not for the FJ), cams, compression ratio, exhaust... Generally all the above working together makes HP. How crazy you go with them affects drivability... Unless you are going to be a desert racer, you don't need to get crazy. You need low end torque for most of what we do...
[/COLOR]2) Is it viable to get a winch installed in a stock bumper?
There winch mounts that are installed inside the stock bumper. US OFFROAD makes one, there are others.