I'm pretty sure that the TDI has a cam belt as normal, the AAZ engine code certainly does, but I'm not sure about the 1Z engine. The cover's easily accessile though. If the car's been run then and the engine will tick verquite happily, then I'd say to just take the car for a run to get the oil nice and warm before changing it rather than using engine flush but that's just my personal preference.
Nothing I can think of potential trouble wise with the engine, although it's probably worth checking the spill pipes as they may well have perished. A good idea to check the tyres for flat spots and perished sidewalls as well.