This is where I was coming from. 1981 vintage versus 2011. Lots of wear, lots of crap in the oil. Best insurance policy is early oil change is it not? I also think about the compression of these engines compared to the gassers. That has to factor into the potential wear and tear.
I think a heathy engine would be a healthy engine, no matter how old it is. I'm not sure what you think is in your dirty oil, but if you're seeing metal or other contaminates, you've got bigger issues. Get your oil tested... It could be cheap insurance that an oil change wouldn't solve.
Changing the oil sooner definitely would be the best policy, but maybe not necessary. You could change the fuel filter every 3k, but is it necessary?
Diesel rated oil is designed to cope with the extreme conditions that the engines produce. There are a lot of added detergents and lubricating additives in there, such as ZDDP. Although (most of) these oils are being deemed acceptable for gassers, I've been reading some conflicting info, but that's another topic.
Something I miss being able to readily do, when I was living at the farm, is that I used to pour about 1/2 gallon of diesel through the engine after draining out the oil.
A friend of mine would dump a quart of clean oil in after daring his oil. I always thought he was wasting his time and money. My logic was, if he wasn't pulling the valve cover off, the oil was only going down the nearest drain.
Personally, I wouldn't worry about the diesel flushing. If you think your engine is that contaminated, either change the oil and filter, or just the filter after 1k of driving, then go back to the normal schedule. I used to do this to all used cars when I first got them. They were gassers, but the oil would be very clean between changes.... no way you'll experience this on a diesel, without some type of bypass filter.
-todd