-1 Diddy Kong - Predictable d-throw into u-air is predictable and DIable by just about any characters above 30%. The thing that makes him top tier (probably top 3) is his insane knockback and reliable finishers coupled with his speed is somewhat unreasonable, but he can be easily gimped if you aren't afraid.
-1 Lucario - An overrated character. His damage output and his rage is insane, but he's not a very consistent character and has a lot of cooldown/starting lag for his attacks. You have to get a good read in to hit someone to 50% and kill him with a bair or something. His recovery is highly punishable, and if you are facing against a character with a reliable finisher i.e Diddy Kong, hten you can easily take him out.
+1 Rosaluma - Very unpredictable playing styles. I see one top professional Rosaluma and then Dabuz's and they have completely different things they do with her. Can auto stop projectiles, can stop grabs (if you are lucky enough to get the frame to stop it), and is still good without Luma. I hear people complaining about Diddy's Uair, but I've seen Rosalina's Uair kill people at 60% with rage at 90% which is insane. Also, Lunar Landing is amazing. Her biggest weakness is her floatiness and that luma's death makes her an average character. However, her floatiness can be cancelled slightly by good setup, and she is not easily juggled because of her outranging Dair. Even with Luma's death, Rosalina is character with great defense.
If I could do more then I would +1 Mario, Luigi, and Shulk, and -1 Sonic, Falcon, and ZSS but I can't so just take the above votes as my votes for now.