@exselsior
At t1/t2
I'm in favor of anything that increases the relevancy of t1/t2 air in the later game, including increasing their fuel.
It only benefits defense in the sense that now there's a limited time that the attackers can maintain their air screen to an extent, and if too many asf need to refuel they can't really attack.
I think there's value here. Let me be clear that I'm not in favor of any kind of fuel reduction that limits the ability to perform a one way mission (or even a couple of one way missions in a row)*.
*This, like everything else, is open to debate.
Your description of the intense back and forth really resonates with me, and I agree it's a core part of what makes the game good. What I'm seeing is that, if the "beat frequency" of that back and forth is 10s or so, more relevant fuel times (in the multiple of minutes--say less than 7) fit around those decisions instead of interfering with them. You know you've got so many minutes to seal the deal with your navy and still have air support. You've got so much time to maneuver your ASF before you send in bombers. Getting that wrong is a misplay, but it's a misplay that can happen every 6-10 minutes instead of every 30s.
Because land and naval units are slow there's a positional element to having them ready. Aircraft, ASF especially, are so fast that positional elements fade away next to the arithmetic (see Ftx's hymns on the snowballing effect). You'd need to slow ASF down to introduce a similar dynamic (thumbs down from me) but you can add a readiness element in the time domain by making refueling more common (it's all about time, anyway, for land units and naval units). Then it's not a question of having them in the right place, but not having them need to go back to the wrong place.
The endless polygon of patrolling aircraft is boring, and it looks like shit (you know it, I know it, everybody knows it). I'm not sure that what I'm recommending would actually rectify that, but it'd be a step away from the status quo of putting aircraft in one pattern and forgetting about them until you need them for something.
Re: Navy, let's not forget about the carriers. I'd say anything that increases the relevancy of carriers as support ships is a positive.