1. Falco spams neutral B as well--is he like them? No, because he spams it differently than doc and mario. Doc has to spam them differently than mario as well, because the trajectory is different.
2. Most of the cast combos off of upthrow against fast fallers. Also, doc has better (read, guaranteed) finishing options out of his CG. Mario doesn't. Or at least doesn't have the ones doc does.
3. Not really. Both use b-throws to get people offstage. Then again, so does every character.
4. So does everyone. Their b-airs aren't actually the same--doc's sends people at a meaner trajectory than mario's does.
5. Doc's up-airs aren't as good at comboing as mario's, and it's much harder to land and f-smash after an up-air combo (though a single, low up-air does). Also, the difference between the two char's f-smash is huge, range and knockback-wise)
6. Doc's f-smash is not one of his main smashes. I'm pretty sure upsmash is used just as much. Also, again, that's 2/3 of the possibilities. Most characters use those two smashes.
7. Except that doc's cape is better suited to it, as it's slightly greater vertical hitbox. Also, mario has a much better recovery (on this topic) because of the benefit of being able to cape to gain distance, rather than just to stall.
8. Because they only use the basic ATs. Also doc has up B cancel, which mario doesn't, and mario has a wall jump (usable after an upB if done properly, which doc doesn't)
9. Except that mario has a better time vs Marth and Sheik because of the differences between them, so not really.
10. You got me there.
According to your logic, almost every character is like mario. You're basically looking at how the moves look similar, even is they are used is different ways. If mario started "spamming b" like doc did, he's get wrecked, just as if doc tried spamming when mario would, or like he tried using projectiles like any other character would. You're acting pretty ignorant, almost as if you don't really know that much about the characters you are talking about.
Yes, they are similar, but not so similar that they *need* to be next to each other on a tier list.