Scabe is correct, we can grab release Wario into a dair, but we can't force an air release without Wario being held above a ledge.
Well I've played Quik and Hunger around my area, never faced them in a tournament just in friendlies. Only time I ever beat Quik was in a friendly with Lucario and I think he was kind of side tracked during the game so he wasn't going all out, with Link closest I ever got was his last stock. Hunger, never played him, I want to but still haven't yet.
Well Wario really can gimp Link if he goes out to try it, seriously thanks to his aerial movement wario can go pretty far out if he wanted to gimp Link.
We all know about the waft, be very careful with low knockback moves, is he DI's right it can lead into a free waft for him.
His air game is much better than his ground game, disgusting air mobility plus near lagless aerials gives him a lot of tools to use. His ground game while not as ground shouldn't be ignored, his Fsmash has super armor and can get you if you don't pay attention. While his air moves are better he is going to have to land on the ground for a kill if he doesn't have a waft ready and your not getting gimped, Uair is an exception to this but Link should be on the ground for the most part anyways. If Wario is trying to juggle you try and get back on the ground and avoid being directly above him.
There is a kind of Wario that I don't think many actually face, the campy kind. I mean Wario that will get a good lead on you and then play defensive as hell. With Wario's air momentum you have to approach him. Projectiles help but his air dodge with his air speed makes it really hard to catch him if he gets a lead. From what I've seen Quik and Hunger don't play this campy, DMG is a Wario that does. I've seen a lot of videos of him playing keep away, it's a pain in the rear to actually catch him.
The less platforms available the better. This is why Battlefield is a bad stage against Wario, he has so much air room to move around and play safe doing poke and prods, and if he can get a lead can play keep away if need be.
Norfair is a definite no go, there are so many platforms for him to abuse with the open space to go wherever he wants, lava can restrict him but trying to catch him is still hard. Brinstar is just as bad.
Every Wario I've played bans FD, it's good considering it is his worst stage, if they don't for whatever reason jump on this stage in an instant.
Another problem is the stage list, Wario has a lot of fun places he can take you, Rainbow Cruise, Battlefield, Lylat, it can go on for a bit.
Remember less platforms is better, so FD and Smashville are the better choices. Yoshi's Island, and halberd aren't bad choices either considering neither is a terrible stage for Link and it doesn't give Wario the run room he could want.
Link should stay ground and keep projectiles going, you need to try and trap him with a projectile and/or Zair. Utilt is a good GTFO me move for Link if he tries an air approach but keep those bombs, arrows, and boomerang going. You need to keep pressure going against him. Jab should help you space against his bite anfd other moves, but for the most part try and force an opening and go for it. If Wario is getting airdodge happy ypu can try to go for an Uair, because the hitbox stays out for a while and try to follow his dodge pattern, but be careful he could try and bait this to go for a waft.
All in all I think Wario has an advantage anywhere from 60:40-65:35. Link can camp and use his sword range to fight Wario, but Wario can gimp Link, doesn't have too much trouble approaching and while he plays hit and run it's a pain to catch him.