He is rather easy to use.
His combos don't do much damage and generally start with a Nair or grab, and those are both dangerous to use. Nair is beaten out by SDI . Grabs are really punishable. Ideally, lucas is attacking into a shield until he gets a shield poke, but that's unreliable, and can even backfire.
I'd count Lucas's strongest aspect as his recovery, not his strength. He can KO decently early, but most of the moves are slow enough that they're either really situational or yomi dependant. That said, Upsmash beats Luigi. Seriously, this is a really wierd fact.
A couple people play him, but very few use him competitively. There's a reason for that.
Most of his techs are pretty easy. I'd say top priorities for a lucas to learn are 1. retreating PK fires, 2. SH autocancelled nairs, 3. zap jump. Now if you look at someone like ICs, you're staring potential in the face, but THAT's a ridiculous learning curve.
He might deserve to go up a couple spots, but like I said before, bad matchups are what's holding him down. And for the record, if MK gets banned, it'll get a LOT worse for lucas. G&W and Marth will become dominant if MK goes down.