Little Help for new diesel owner

I have just bought my first diesel (2005 cummins 5.9 6speed 4x4 quad cab short bed, 53,000 miles!). It came with a leveling kit and 35/12.5/20s and a k&n intake, besides that its all stock. I want this truck to last a long time and I do not plan to run a programmer or any mods.
Wondering if the 35/12.5/20s are going to lead to a lot of wear and tear on the vehicle and lead to a lot of extra parts needing replaced up front. also the power steering in already leaking. The wheels looks awesome but wondering if I should just go to a stock wheels with 33/12.5s? Also was going to replace all fluids with amsoil. Just replaced oil with mobil 1 for turbo diesels 5-40.
Also since im not doing any mods is all the extra dual fuel filters and coolant filters ect. something I need to do? any advice helps, thank you.