Looking at a 2006 F250 with 108000 miles on it Lariat my first diesel and hearing about no capacity to tow, blows engine, what's the real deal, and international built this engine checked the vin code. Suggestions

Have a qualified diesel mechanic check it out top to bottom. If it passes inspection, change all fluids and filters--then you will know where you stand. Follow Ford's maintenance schedule, start a maintenance log, and you should be fine. P.S. I would only use full-synthetic heavy duty diesel engine oil--turbos demand it. If you need a real work horse, buy an older Ford 7.3L PSD.