PSU and GPU compatability

Yeah that is fully compatible. Its rated requirement is 450W. :)

Oh, if fan is set on auto, its speed would increase in accordance with GPU's temperature as an effort to keep it as cool as possible but if you don't want to take any risk, you can manually set the fan to run at a fixed % all the time. That might get a bit noisy because normally 100% fan speed isn't very quiet but would help a bit in keeping it cooler.

Otherwise you can opt for water cooling to ensure things.