Thistledown, perhaps I among other spoiled your first impression of the boards, normally we don't post and critique at the pace we've done here
Let's see here then:
Pixie
[spoiler]First of, two-weapon fighting and Flyby Attack don't really mesh. Full-round attacks aren't compatible with flybys, and the only time TWF kicks in is during the former. Greater Flyby isn't that impressive either, since it's a straight line.
Dipping cleric has never been a bad thing in general, at least as long as you pick your domains carefully. Luck and Freedom is good choices.
Dipping another level in Swordsage is also an idea, or even two (kicking cleric and exemplar) for Dancing Mongoose and Tiger Claw Maneuver X to qualify.
However, there is no denying that a single dip into cleric is better than the 3rd level of swordsage, especially considering the spell list you gain and the help it provides for UMD purposes.
[/spoiler]
DFA
[spoiler]The DFA build is very detailed, though we don't need a level-by-level progression most of the time.
You've listed Frightful Presence at two different levels, as an invocation and as a extra invocation through feat.
Pick it once and then go to
Drow of the Underdark and get yourself Imperious Command. Trust me, that will be awesome
I don't see the reason why you should multi-class a DFA with warblade really.
Sure, you net some HP and some maneuvers, but you loose out on Force Breath and a d6 of damage (and immunities, how much difference those makes...).
You take Wall of Blades, but any serious melee monster (not necessarily a monster per se, might as well be a normal halfling for all purposes) WILL have a better attack bonus than you. Remember, DFA have wizard BAB; your BAB is 11.
Iron Heart Surge is a good maneuver though, I'll grant you that. But it's also available through Martial Study or as an Item (the book talks about this around the section about White Raven Crown).
Action Before Thought is the Ref substitute?
Ref tends to be the least important save, just a thing to keep in mind.
Sure, you do get some nice stuff, but Force Breath will really, really help when you're up against that thing with immunity to both cold and fire. Or just helpful in general, killing of incoporeal stuff, ignoring most effects etc.
I'm more inclined to go straight DFA, especially if you can get the item version of the better maneuvers.[/spoiler]