Hi bendybead, regarding the mileage you can rarely go wrong with a Honda Diesel. I have a Honda Accord with the same 2.2l diesel and it has nearly 160k on the clock, with others on the market with up to 250k. With some research I’ve found that the turbos are reliable (again my car has the original). Finally the DPF filter will only really block up if your doing short, stop-start journeys, However, a long journey of above 40 mph for 20 minutes should clean it through.
I’m not an expert as I’m new to driving so other perspectives might be useful. However, thought I could help I had similar questions when considering buying my own.