A slim 360 mm radiator can be used to cool a 250 W heat source, if you accept high fan speeds but still rather high water temperature. From the latter follow low boost clocks of Threadripper.
No, it does not.
Well, you may still need to remove dust from radiator fins occasionally.
ed: perhaps I should have asked, *how* do I achieve a loop that doesn't require a yearly drain and refill. Maybe I've just been reading the wrong info?