Heck, try all the changes and find out. That's the beauty of our hobby.

Now, about some of your expectations.

Weigh your gear before you swap in the CF. I've yet to find 40 size CF that's lighter than the usual aluminum nor 60-90 size either. It's not a given that CF is lighter than what's found on lots of ARFs.

There really are savings to be found in wheels, but only if the OEMs are heavy. Want to save weight in the gear? Get rid of the axles, weigh your wheels and see if they can be swapped out for lighter and THEN.......... Then swap out those axles with CF tubes in aluminum tubing. Epoxy the CF into the tubing and the tubing into the holes in the struts. Takes time? A bit. But you'll get an honest weight savings. I've got a number of old (built 5 years ago) ARFs that came with HUGE iron (ok, metal) axles that got the custom made axles. They do take plywood plates sandwiched against the strut to fully support the composite (REALLY composite : aluminum+CF) axle. The struts aren't thick enough without additional thickness and that small amount of ply is perfect.

And then...........
and then.............
Go fly the sucker and report back. Good chance you'll think it's awesome.... first couple of times you take 'er out........ and then............ you'll notice that getting a good needle setting instead of a bad one makes more difference. But that's not a given.

Everything is worth trying.

I'd bet that swapping the prop might do as much. And double the bet if you took 4 or 5 props out and tested to find the best.

It does sound like you're got something worth trying. Let us know how it works out.