The ever popular Downair->Upsmash, jab jab Shine, techchase Upsmash at high %, simple Bairs (I'm good at using Bair thanks to Kirby experience, I guess... Fox's is faster, stronger as a kill move, but harder to control, since it has a lot of ending lag in the air like Kirby's Nair)
Fox is good at gimping with Shine... Upair is a good kill move since Fox freaking zooms into the sky so fast and Uair comes out so fast..
Also, lasers are good for refreshing kill moves better than Kirby's pummel could ever hope
Fox is so underrated
These are good points, but... Dair>Usmash is about as reliable as Kirby's Dair>Fsmash, by which I mean it can be shielded.
Jab>jab>shine isn't a kill setup.
Techchasing... well, that's not really a kill setup either. A lot of characters can tech-chase for a kill, and to my knowledge Fox isn't better than anyone else at causing that scenario.
Fox's Bair is faster? What exactly do you mean by that, because I'm pretty sure Kirby's Bair comes out faster. That being said, yes, it is a good killing move, but is it as easy to land?
Uair too is a good kill move, I agree, but isn't it a two hit move like Falco's that you can SDI? Also, it's kind of easy to see coming (though I'll admit not as easy to avoid).
Shine gimps, yeah, that's true. On the flipside, Kirby is awesome at gimping as well.
Lasers do refresh moves better, I'll admit. That being said, pummels refresh moves really well as well, so I don't think it makes a huge difference, not to mention pummels can't be blocked (though lasers require no setup and are safer).
I'm not saying Fox is bad, but it really does seem from what you said that Kirby has more kill setups/options. Meh, I dunno... feels that way any way. I wouldn't say he's underrated per se though. He's a great character who's weight/fall speed and vertical recovery is keeping him down. I mean, pretty much any gay thing you can think of works on him.