My Aurora is being set up with a 24-38-48 rings but the 30-32 gear has worked for everything I've done so far. I don't even need the lowest gear to climb the 6% hill to get back home with six bags of groceries. Only time I've used it was for a 12% hill while riding in cold, wet, rainy conditions where my body was likely stealing blood from my legs to keep my core warm. I probably won't need the new lowest gear for anything but the most extreme climbs while fully loaded.

A 26T should work fine with an 11-32, but a chain keeper could be necessary with the 16-tooth drop from the 42T. A 28T ring should work fine with an 11-34 too. You should verify the chain is long enough before installing the 11-34 though. I don't think I'd use smaller than a 28T with an 11-34. It usually works but pushes the rated capacity of the rear derailleur farther than I would care to.

The LHT is almost like driving an F-250. Are you going to haul that much that often? I get by just fine with my mid-size Aurora and my compact Double Cross. They get much better mileage.