Kirby tends to stay pretty grounded actually - aerials are important but Kirby is SIGNIFICANTLY more grounded than Puff. Kirby will also stay grounded more because he can duck our stuff. He'll attack from the air, but he's going to approach on the ground because shielding and ducking [and even rolling] are options he maintains grounded, and his air speed is atrocious.
For gimping, if they're ledge level, nairing after the third hit of fair if they do it carelessly is a great edgeguard since you'll run him out of jumps after doing this once or twice, at which point you just have to grab the ledge and roll [the airspeed on final cutter is nearly nonexistent].
I know this having played Triple R [I was truly trash before, but I have played him] and if you watch his Kirby you'll notice he's not all that airborne outside of committing to a close-range attack or a tomahawk. Also, Kirby's bair OoS is more dangerous than his fair, so if you try any jab pressure tricks, you want to do them from the front [fair is easier to CC shield or whatever, and I think fair is a little slower]. Kirby has a 3-frame jumpsquat, so even though his aerials are about average speed, they're good OoS options.
Here's a video of him playing to help illustrate some of what I mean [it's not versus Link, but you'll hopefully see what I mean about him approaching while grounded]:
https://www.youtube.com/watch?v=alccs3CrFXI
Also, I think it's worth adding this to the guide section as a warning about something to avoid:
https://www.youtube.com/watch?v=6g1kTaDg1U0