You tend to have a campish style of gameplay: you roll dodge all the way to the edge, and then rush in - that was especially evident with your Sonic - or you let the opponent come forward as you do with any projectile character.
Your biggest weakness is that. It's predictable. People know what you're going to do next. Try staying with them and bringing the fight to them. Playing offensively at times when your opponent is off-guard is a great way to mix it up.
Try adopting different styles and mixing up which one you do based on your current situation - it'll prove far less predictable.
Second, I need to face your Meta-Knight, but from what I've seen, stick with Lucario.
And if you're like normal people, yeah, you'll lose some skill by not playing it for a while, but if you're like me, you'll be rusty at first and then suddenly become better, so hope you're like me XD