Well, Wiseguy, it took me a while, but I have compiled my own list and am ready to put it here for comparison with yours. My list is mostly the same as yours, so first I'll just pass over the characters who are the same, then make some commentaries on the changes I would have made, and why. So without further ado, here are the parts that are the same:
1) Mario
2) Luigi
3) Peach
4) Bowser
5) Link
6) Zelda/Sheik
7) Ganondorf
8) Midna or WW Link (I'd rather see Midna, and consider her to have greater chances for various reasons.)
9) Pikachu
10) Jigglypuff
11) Pokemon Trainer
12) Kirby
13) Metaknight
14) Dedede
15) Fox
16) Krystal
17) Falco
18) (Zero Suit) Samus
19) Ridley
20) Donkey Kong
21) Diddy Kong
22) Ike
23) Micaiah
24) Captain Falcon
25) Lucas
26) Yoshi
27) Wario
28) Pit
29) Ice Climbers
30) Game & Watch
31) Captain Olimar
32) Animal Crosser
33) Solid Snake
34) Sonic
35) Megaman
Now, not all of the choices I make are entirely different from yours, I have just made slight adjustments for my own reasonings, which I will give.
1) Excise Geno, and just go with Bowser Jr.
---Think about it, Geno is a third party character, and with three others who are either in or have a much better chance of getting in, Geno is out, IMO, even though he'd be an interesting character. Unless you're to assume that Megaman is not in, but I highly doubt it.
2) Mewtwo would be interchangeable with Lucario
---It's not like they'd be the same, but I'd say they both have equal chances of getting in, considering that while M2 has the advantage of being from the earlier smash games, and being from the original game, Lucario is more current, and promotes the more recent Pokemon games better, which you'd think they want to do. If one appears, I'm sure the other would be a pokeball. For the sake of being clear, though, I would think Mewtwo has a slightly greater chance, but that's just a hunch, and I can't think of a good reasoning for it.
3) Marth shall be interchangeable with Takamaru
---Your own distaste for Marth aside, the fact that he appears in the most FE games out of all the lords is very significant, as is his appearance in promos for the next upcoming game. Furthermore, as you yourself point out, he is the face of FE. He is interchangeable with Takamaru because of the latter's popularity in Japan, which you mention. For the sake of being even more compromising, I would also consider those to and Micaiah to be in a situation where two of the three would be in. Their advantages and disadvantages seem to be in that kind of limbo.
Further, Marth and Ike are far from clones, as we've seen from the brawl demo. They have one move vaguely in common, but that never stopped Mewtwo from appearing with a similar move to Samus, and it seems even now that Kirby and Metaknight will have the same throws. Hmmm. Face it, Marth is more likely than you would like him to be.
4) Kawashima = gone.
---Kawashima Ryuuta was a real person before being put in the game, and he still is. If you'd be so kind as to read the stickies, you'd know this means he's out, without a doubt. Really, I wonder what was going on in your head here.
5) Sukapon = in.
---So you want a WTF character? I like the idea of Sukapon. No one knows who he is here, yes, but his historical significance is important, in my opinion. He (it?) was the first fighting game character on a Nintendo console. If you take into account the reasoning for G&W being in Melee as an important figure in Nintendo history, you'll see why Sukapon makes so much more sense than Kawashima.
6) Excise Simon Belmont
---Well, since I've already committed my decision to three 3rd party characters, which was the max stipulated by Sakurai, I can't see Simon Belmont appearing in Brawl, which saddens me greatly because of the emblematicness of the Castlevania series. Unfortunately, the reason already listed, plus the fact that there's already a Konami rep, just makes Belmont seem to not have a very good chance.
7) Isaac or Claus shall be included, but not both
---Well, you know as well as I why either of these two should be included, but IMO they seem the most likely, all other things considered. Look through your own runners up. Is there anyone else that is more fit to be in the game?
That's the conclusion I've come to, personally. Feel free to shoot it down, or ignore it entirely.
Edit: Hmm, I seem to have counted wrong. You might as well just include both Isaac and Claus in my own list, then.
Also, I have a wonderful addition for your 3rd Party runners up: Rocket from "Rocket: Robot on Wheels." No one played this game except for me, but it was probably the most enjoyable gaming experience I've had in a long time, and as a one-wheeled fighter, you can't deny that Rocket would be a unique character. I even imagined up a moveset for him, but I haven't posted it because it's not likely to ever happen.