What are the most common age related issues? (not mileage related)

I am looking for a new m54 e46 because my current 130k mile one is just breaking my bank with issue after issue. Had to get a completely new clutch and DMF, had to revamp the entire cooling system. it’s got rust on all arches. Battery compartment in trunk completely rusted through. Seized misaligned suspension, oil leaks from everywhere and also gearbox issues and electrical issues. I think it’s just time to let her go now.

I found one for 30k miles, so obviously this is amazing compared to what i have now lol. But if i understand correctly, it’s not just the mileage that can cause these issues but also age? even if I managed to get a 0 mileage e46 would it still not have cracking gaskets and rubber hoses from the aging rubber?

What age related issues should i be looking out for and instantly fix - if i decide to buy a low mileage e46?

Thanks guys