Link definitely takes some research just to be decent.
As far as Lucas goes, try not to dodge him, a lot of his moves have that duration on them, that hits you after you dodge, also never get hit by his upsmash it is keke. His recovery is much larger to gimp than Ness' but if it does hit you, it isn't that big of a deal. I block a lot versus Lucas, since his shield grabbing isn't that bad, Lucas is kinda light so KOing him isn't so bad. Don't get hit by that bat, but you can dodge the bat at least, or block. His PSI thunder, is really annoying, get used to AIR Dodging it multiple times, careful about getting hit by the tail of it though. The PSI thunder can KO you, Ness' is a lot easier to deal with. If he tries chasing you off the Edge, just nail him with a Fair, it should have priority over his Fair, if he hits you with his Fair that is trouble, also you could just hit him with your rang, I would not use a bomb, b/c you might fast fall, you gotta be real careful when pulling those out. Do not try using your Zair versus him and Ness, unless you are really good with it, they are hard to hit.
Small characters are a pain, anything that is hard to ZAIR is a harder match in general.