A TRD S/C kit gives (according to the official figures) a little north of 300 crank horsepower (in actual 65 crank horsepower and another 65 lb-ft of torque over N/A). A smaller pulley on the S/C would yield maybe another 30-ish crank horsepower. With the transmission losses, you're looking at around 240-ish wheel horses (20%-25% loss in the 4WD transmission).
The biggest problem with supercharging is that it requires power to run a supercharger, that power is taken from the nose end of the crankshaft. Not only does it reduce output power at the flywheel, it also puts a radial load on the crank journals. You can only overdrive a supercharger so much before you start to prematurely wear out the nose-end journal. Almost always, a turbocharger will produce more power than a supercharger for the same boost level.
For turbocharged engines, jumpy torque curve, not quite, yes you have to factor in turbo threshold and lag, but if you get used to it, it's not going to be an issue (you can use brake torquing and you can get on the throttle earlier, you also have anti-lag). As for the blow-off valve, only the free-air venting BOVs are noisy. The civilised ones blow-off back into the intake tract. You can hardly hear them when they operate. Inevitable overheating issues? Again, if the cooling system has been designed for the power not the displacement, there won't be any issues. Obviously, putting an engine into an engine compartment that makes roughly four times the power of the original motor, you WILL have cooling issues, mostly due to airflow extraction. But, if airflow and radiator sizing are properly managed, a turbo charged engine will not heat up any more than a N/A engine. Keep any engine lubricated and temperatures of the fluids at the right level, reliability will not be an issue.