Fixable problems. Probably some pulleys, tensioners, and loose belts too. Fixable problems. If they are related to the pulleys etc they should have been done during your radiator job. The mechanic who did it should have checked all of this (takes 3 minutes) along the way, its being professional.
Don't worry about the terrible sounding engine. All the issues are fixable. Do the fuel filters and run diesel through your fuel tank to clean the injectors. Clean out the ICV (idle control valve). Check and clean or replace all the spark plugs. Clean the throttle body. I'm sure your engine will run really great. It just sounds clogged.
You mentioned the throttle position sensor earlier. In my experience, that usually does not go bust, but it helps to clean it and its connector with contact cleaner before you reconnect them. Ideally, after cleaning, coat both the connector and TPS with dielectric grease before you reconnect them back.