Smee, from your list, I've been lucky enough to do two of your wish list (almost 3).
Australia is wonderful but for me I wouldn't bust a gut to see Ayre's Rock. There are many better places in Aus to visit (eg Sydney with Harbour Bridge and Opera House, Great Barrier Reef, Gold Coast and the real gem, Tasmania. Tasmania is a lot like Scotland was about 25 years ago (quiet and shut on Sundays!!), but well worth a visit.
We have friends who live in Cocoa Beach, Florida right next to Space Centre. You can actually watch the lauches from their home. A few years ago our friend (who is ex US Air Force) got us tickets to go onto the Base to watch a launch from the perimeter road. Absolutely awesome.
I also lived in BC, Canada when I was in my early 20s and have done the hunting and fishing bit. But in BC it is mainly Sockeye salmon, not steelhead
Like you, I have the Grand Canyon still on my to do list.