My brake rotors wore out before my brake pads, had them replaced at 40,000km! Had the pads changed then too just so the new rotors would last. I replaced my rotors again with DBA slotted rotors about 70,000km ago (about 200,000km on the dial).
As for fuel economy, it depends on where I'm driving. Gentle city driving (not Sidunny) where you don't have to stop too much I'll get about 11.7-12LPHK. A bit busier city driving or the average for driving from my home out in the country into Newy (a mix of 100/90/80 zones mostly) and I'll get about 12.4LPHK. If I use the freeway instead (110km/h) it'll use 12.7LPHK.
Then towing. 2.5T 8.5m caravan 3.2m tall - general flat-ish highway driving gets about 16LPHK, introduce a few hills and it goes to 18.5LPHK and introduce more hills and she's up at 20LPHK. We recently drove from our place down the freeway to Sidunny and out to Sidunny Motorsport Park where I worked (on post 4, the vehicle return gate of the circuit) and got 20.4LPHK. Not entirely happy with that, but there was a fair bit of fog on the freeway and a LOT of traffic on the way down on the Friday - Pennant Hills Rd is a bloody pig of a road on Friday arvo - didn't help much at all.
Has it changed much? Not really. If I cruise on the highway at about 90-95km/h (not towing) I watch the thing doing around 10LPHK. As good as when I bought it.