Well, you could go human swordsage 7/crusader 3, or human swordsage 10......
With the multiclass one, you'd have 5 stances (2 swordsage 1st-level, 1 swordsage 3rd-level, 1 crusader 1st-level, and 1 crusader 3rd-level) and some nice abilities. Could learn Stance of Clarity, Flame's Blessing, Assassin's Stance, Martial Spirit, and Thicket of Blades. Feat-wise, EWP: Spiked Chain as the human bonus feat, Weapon Focus in Shadow Hand weapons (which include the SC) from the swordsage's Discipline Focus feature, Adaptive Style as the 1st-level feat, Combat Expertise at 3rd, Improved Trip at 6th, and either Combat Reflexes or Two-Weapon Fighting at 9th (the other can be chosen later at 12th). Put the 4th and 8th level ability increases into Wisdom or something.
Initiator level would be 8 swordsage and 6 crusader (need the crusader levels to come after the swordsage ones; though the 7th level of swordsage could be taken last). Maneuvers could be Crusader's Strike, Charging Minotaur, Stone Bones, Mountain Hammer, Foehammer, and Revitalizing Strike from crusader levels, and Burning Blade, Distracting Ember, Shadow Blade Technique, Sapphire Nightmare Blade, Mighty Throw, Emerald Razor, Cloak of Deception, Flashing Sun, Death Mark, Insightful Strike, Zephyr Dance, and Bounding Assault from swordsage levels.
You'll be able to stay reasonably mobile, while using occasional combos like Flashing Sun + Burning Blade + Assassin's Stance, or Flashing Sun + Distracting Ember + Assassin's Stance, or Flashing Sun + Cloak of Deception + Assassin's Stance (if you have no allies flanking at the time, you can get your sneak attacks in through CoD's greater invisibility or through Distracting Ember's flanking fire elemental) to make several sneak attacks in one full-round action (using your chain as a double weapon for that round rather than a two-handed reach weapon; with your BAB of +8/+3, you'd be making 4 attacks with Flashing Sun and Two-Weapon Fighting, at +4/+4/-1 with the primary hand and +4 with the off-hand).
The rest of the time you can rely on moving around and pushing enemies around, using Bounding Assault, Charging Minotaur, and Mighty Throw (which should be useable with the spiked chain since it's a trip attack, just with the added effect of throwing the victim). Later on you can learn better throws, swapping out Mighty Throw for a damaging one like Comet Throw or Soaring Throw (probably around 10th level swordsage). You'll have a few counters and boosts at your disposal, like Counter Charge and Zephyr Dance. When you get the chance, swap out Burning Blade for its higher cousin Searing Blade (probably at 8th level swordsage).
And of course, you should soon learn Ruby Nightmare Blade, Searing Charge, Obscuring Shadow Veil, Disrupting Blow, Bloodletting Strike, Shadow Stride, or Elder Mountain Hammer. I suppose that of those, DB, and SS would be the most useful ones for your theme (DB to knock foes senseless for a round so you and others can move around unopposed, and SS to escape an opponent's melee reach after you attack with a standard action (since Shadow Stride is a move action).
So you might learn DB and SS at swordsage levels 8 and 9. At 10th and 11th you may want to learn Desert Tempest and Greater Insightful Strike (or Scorpion Parry, if you're worried that GIS might be too strong and give the group a bad impression; it probably won't be, since you don't have any Concentration-boosting magical or psionic items).
Your other strikes will help with accuracy and dealing more damage, or healing a few of your wounds (Crusader's/Revitalizing Strike). Steely Resolve 5/Furious Counterstrike will often be active and providing you with +1 on attack and damage rolls, and the crusader's Zealous Surge will sometimes be useful (your saving throws will be fairly high anyway, and when you later gain 8th level in swordsage you'll also get +2 on saves from Discipline Focus, as long as you're in stances from a particular discipline). Insightful Strikes from Discipline Focus would probably be best allocated to Diamond Mind, since a slight majority of your strikes will be from that discipline (later it can be applied to Desert Wind or Shadow Hand as well).
You'll probably focus on using swordsage maneuvers in battle, but initiating Crusader's Strike and Revitalizing Strike whenever they come up as granted maneuvers (if you're injured at the time). And when foes with DR pop up, or you can't spare a round to use Adaptive Style, you can rely on the crusader's Foehammer, Mountain Hammer, Stone Bones, and Charging Minotaur. Most likely your 5 readied crusader maneuvers will be all but Stone Bones, since you'll be reasonably tough anyway and will want to use the others more often (whenever you actually face a foe with tough DR, you'll want to have both Foehammer and Mountain Hammer ready).
Typically you'll be in the Thicket of Blades or Martial Spirit stance, depending on whether or not you expect enemies to try escaping from you (if not, then just use Martial Spirit so you heal 2 HP each time you hit someone). Assassin's Stance is for use when you expect to rely on full-attack actions (or on Flashing Sun, which grants a full-attack), and maybe for use between encounters (so if you win initiative in a fight, you might be able to move in and hit with a sneak attack before the opponent is no longer flat-footed). Flame's Blessing is for when you're facing enemies who favor fire-damage attacks, and Stance of Clarity is for occasional situations where you're facing a single enemy (though others may be attacking your allies) and you aren't expecting to run interference for the rest of the party through Thicket of Blades.
If you go for straight swordsage 10, you'll have some more maneuvers at your disposal; just pick the extras from among the others already suggested. You'll be at least moderately less tough, and won't have Thicket of Blades, but you'll probably be a bit more mobile. The Pearl of Black Doubt stance or Hearing the Air stance may be best for your 4th swordsage stance in that case.
Either way, a chain shirt or mithral shirt of +1 or higher enhancement would be good armor for you, and the spiked chain should probably be +1 with an ability like Shocking or Frost (you'll already be capable of fire damage, so it would be handy to have access to another energy type; though Shadow Blade Technique can deal 1d6 cold damage sometimes).
