Before I start, I have to say that I like this class, and I find to premise very interesting, and it's nice to see some TWF love once in a while.
However. I have to agree with the others here, these could easily be a single without radically shattering the balance, and twf with 3/4 bab almost always degenerates into a flurry of misses. And people don't dislike seeing lots of class features, they dislike dead level. That's why wizard, sorcerer and clerics are never played passed 5th level if one can avoid it, and why fighter is a 4 level class unless one goes the dungeoncrasher route, because people want to get something more than just more/bigger numbers at every level.
Also, the capstone is pretty weak, as pretty much everybody who wants can get pounce (and whirling frenzy/rage while they're at it) for a 1 level dip into barbarian. As written, it is mechanically almost always better to take that 1st level of barbarian instead of a 20th level, and it can be taken at any time.
As for the armor bonus being too high, remember that they can only use light armor (losing more or less 2 to 3 points of AC) and that not only does AC become less and less important as the character levels (more mobs target saves instead), but most monster's attack bonus scales much master than AC reliably can. I'd even recommend adding some source of miss chance (blur like effect maybe?) as an invocation.
And as for arcane alactricity being too powerful with a full attack, warblades can do it at level 17, and with Raging Mongoose added in for even more attacks (or heck, revenant blade gets timestop, but better, at 20th level for one round and still get Raging Mongoose or Time Stand Still).
EDIT: You might also want to let both these classes count as rogues for the purpose of bypassing uncanny dodge.