Raging Swordsage

[Cwymbran-San]

Simple question that i can find no answer to: Can a Barbarian 1/Swordsage X still initiate maneuvers while raging?

I would say yes (apart from Diamond Mind maneuvers requiring a concentration check), but i cannot find a corresponding rule.

[RoyVG]

Like you said, the Diamond Mind maneuvers that rely on Concentration are off limits because you cannot make Concentration checks during rage, but other wise, you can use them. If there is no rule against it, you can use them.
I think for Stone Dragon and Tiger Claw maneuvers rage is especially fitting and some Setting Sun maneuvers benefit from the increased strength as well. It's also fitting for Iron Heart if you are a Warblade. Heck, the Bloodclaw Master' Shifting ability is similar to a rage (it says so in the description!).

[Chronos]

Well, barbarians can't do anything that requires patience or concentration while raging, and you could maybe argue that some specific maneuvers that don't require concentration still require patience. I can't think of any specific good examples for that, though.

There might also be some maneuvers that require some other prohibited skill... Is there anything that requires a Tumble check, for instance?

Other than that, though, there's no restriction.

[Tibbaerrohwen]

There are barbarian ACF that allow concentration, though I believe they are from Dragon Magazine.