A while ago, I proposed using a changeling warshaper, but the thread filled with arguments about the legality of its abilities with only minor change shape, even after I said that the DM had looked through the relevant rules and told me that if it didn't break the campaign, I could play it regardless of whether it was legal by RAW.

So, I looked back and thought, "how could it be legal?" The obvious answers were druid or transmuter or somesuch, but those were counterproductive - If I'm going to play a wizard or druid, I can do anything I want, when I want to anyway. Then I found the Cabinet Trickster prestige class.

Cabinet Trickster, for those unfamiliar with it, is a prestige class from Races of Eberron for changelings that makes a changeling more like a true doppelganger. As part of this, at fifth level, the changeling in question gains the Change Shape ability - one of the abilities that is supported by the Warshaper's abilities.

So, with this in mind, I altered the character concept more towards a rogue/assassin than a straight-up meat tank, though with warshaper's fast healing healing, that might be viable as well. If I were to play it in the future, what would the optimizers of the playground recommend?

Cabinet Trickster requires 9 ranks of disguise and one feat, and Warshaper needs +4 BaB and, for the purposes of this character, Change Shape.

Here's the prospective build:

1 - Rogue(Changeling Sub), Persona Immersion(Prereq)
2 - Swordsage(Shadow Hand Focus), (Island of Blades, Clinging Shadow Strike, Mighty Throw, Sudden Leap, Wind Stride, Sapphire Nightmare Blade, Counter Charge)
3 - Swordsage, Adaptive Style, (Stone Bones, Stonefoot Stance)
4 - Swordsage, (Shadow Jaunt)
5 - Swordsage, (Emerald Razor)
6 - Swordsage, (Dance of the Spider, Devastating Throw), Martial Stance(Assassin's Stance)
7 - Cabinet Trickster
8 - Cabinet Trickster, Quick Change(CT Bonus)
9 - Cabinet Trickster, feat???
10 - Cabinet Trickster, Racial Emulation(CT Bonus)
11 - Cabinet Trickster
12 - Warshaper, feat???
13 - Warshaper
14 - Warshaper
15 - Warshaper, feat???
16 - Swordsage
17 - Swordsage
18 - Swordsage feat???
19 - Swordsage
20 - Swordsage

Assume a high-powered point build ability set and a focus on strength and constitution. I may switch out one level for barbarian for speed bonus. The character is supposed to be highly mobile and strong in melee as well as able to sneak around semieffectively when necessary. Kind of a tall order, but the warshaper abilities running 24/7 covers a lot of sins if I live that long. Until then, I'll be much more rogue-y.

What I'd like to know, mainly, is:

Will it blend?
Does it look solid at each level, or does it have weak spots or stetches?
Are there selections I made with better alternatives?
Does the build do what I think it does?
The spot were the feats are unspecified: any good choices for them?