Look through this. You will need to do the procedure listed for full flush to get all the old G-11 out. G-11 and G12 aren't compatible. So flush with water before filling with coolant.
The weakest factory hoses are probably the ones at the back of the engine near the EGR cooler. They're exposed to a little more heat being next to the exhaust manifold and turbo. Otherwise the hoses hold up pretty well. I replaced the Y-shaped hose under the injection pump because I installed a coolant heater (there's also a writeup for that). If you have a fuel leak on the injection pump it will drip onto that hose and diesel fuel melts rubber hoses. Any other hoses that you replace would just be preventative maintenance, I can't think of any specific weak spot.
Also look through the new owner checklist. It should bring the car up to current maintenance. While you are replacing all the hoses also inspect all the wiring for chafing, rubbing, or cracks.
Also check the harmonic balancer pulley. If it's original because the original design tends to chirp. There's a wirteup for it in the "how to" section.