I agree that hoses are made much better than a few decades ago. I too used to change all the hoses as a preventive measure. Now when I do it, the hoses seem rather healthy and I realize I'm wasting time and resources. IMO, Five years and 65,000 miles may be a bit too early (we live in the same climate). Ten years/100,000 miles may be more appropriate. As long as you keep poking your nose under the hood, you should be okay.
But you should go ahead with a coolant flush and fill every two or three years. If read betwen the lines correctly, you may have heard stories where people flushed their neglected radiators, only to find that they flushed out crud that sealed the leaks and now the radiator leaks (happened to me twice). This is poor use of logic. You should flush any accumulated crud out to prevent poultice corrosion - both radiator and engine water passages. If the radiator leaks afterward, then you were "skating on thin ice" with the old radiator anyhow, and are forced to make a repair that could have happened on the road.
95 E320 Cabriolet, 131K