Damn it, just as I'm about to start playing as a Innovator. I really like that archtype, but it is kinda the best one. Maybe toss on a crafting focused one instead? Or I guess you could unbreak the artificer rogue archtype, but that seems like way more work when you could just be a tinker gnome engineer.
Also, I would personally recommend keeping the DSP powers, it encourages people to use their overall balanced material, while still maintaining the freeness inherent in your chosen system.
EDIT: Might I recommend having the Landsknecht's greater power be allowing them to make any number of attacks against charging enemies when set against a charge or something like that? Or maybe that's how it already works and I can't really see it in the places I'm looking.
EDIT2: Or maybe not that because it's 1400 GP in MIC.
EDIT3: The feat Hold The Line also gives you an AoO against all the opponents you meet once you've got a large enough reach.
EDIT4: You know though, the Sentinel really doesn't get to make that many Attacks of Opportunity, due to the fact that it's a heavy armor frontline fighter, and you'd have to run Dex as well for Combat Reflexes. Maybe they should get an ability that either gives them more or lets them use another stat for it.
EDIT5: Oh, maybe they could get one additional AoO per round for each enemy within reach of them.