I'd accept these characters if they're included, but they wouldn't make me very happy...
Sora: I believe because the character inherently contains non-game originated content (his keyblade has a Mickey Mouse logo for a keychain...), that he'd be a slippery slope to non-game originated characters... and I don't want that. Sure, he's a cool character, and he's from a monumentally popular franchise... But it is Disney, and that's a minefield I don't want Smash to trespass on.
Geno: I'm not really a fan of irrelevant side characters that aren't very important. It made me nervous hearing that Sakurai wanted him. A better representative of the Mario RPG side series would be Paper Mario himself, not a character that only appeared once, and wasn't even very important in the grand scheme of things... just popular and cool.
Another Fire Emblem character: We have enough, let's wait until after the next Fire Emblem game to come out to get another, maybe as DLC. Right now, we have plenty, and not enough variety among them either.
Ashley: I like this character well enough, and I can't say I wouldn't be at least a little bit happy to see her, I do want to see more Wario Ware reps after all... but, she's not very important to the Wario Ware series. She's about as important as any other side character. And the problem there is... why her? Why not Jimmy T? Mona? 9-Volt? They're all equally important, so I'd say the same for any of them too, really. But that's sort of the problem. If this character doesn't do enough in a game to stand out among the crowd, I don't feel like she'd be important enough to be playable. She's just... popular. Sure, popular within Nintendo as well as with fans, so I guess it'd make enough sense to include her. I just wish she was more deserving of a character to get in.
Crash Bandicoot: I just don't think Crash is a gaming icon, or a Nintendo one... Just, well, he's not big enough. Heck, Rayman barely is, but I'd understand him getting in because of Nintendo and Ubisoft's relationship... But Crash? He's a Sony icon, but I'd argue he isn't a gaming icon, he never reached the levels of Sonic, and compared to other characters like Banjo-Kazooie, he was never a Nintendo icon either like they were. I just don't see what good he'd do on the Smash roster. Metal Gear and Final Fantasy are both bigger gaming franchises worthy of characters in Smash, but Crash just ain't on that level in my opinion.
Shadow the Hedgehog: eeuugghhh.... I know he'd just be an Echo, and that'd be an easier pill to swallow, but... eughghh... This character is almost as bad as Dark Pit, but at least Dark Pit is Nintendo. I'd much prefer Tails, at least he comes from a better generation of Sonic games.
Bandana Waddle Dee: What the guy above me said. He's just a Toad/Goomba with a hat. He was a desperate attempt to add a fourth player in RTDL, because, the truth of the matter is, the Kirby series only has three consistent and iconic main characters. Waddle Dee is just the extra they had to scoop up for gameplay purposes... he doesn't matter nearly as much as the other three, and in my opinion, nowhere near enough to deserve a playable role in Smash. He's not a hall of famer.