From what I can tell the leaks look to be part of the silicon that the chips are made out of. And I can't tell what the chips do without the schematics for the MB, which aren't available to people like me lol. But they probably have something to do with the SATA controller.
I really have issues with sata 3.0 for the last one month - random freezes. You are knowledgeable indeed - I could not figure out after sleepless nights.
It looks like there may be some sort of short or ground inside the board inside the SATA controller which is causing the cheaps to overheat. Contact the manafacturer and get them to send you a new one through warranty.
OMG To me it looks like it's something from the solder. Or actually like they used some organic compound clue to attach these things to the board what liquefies when heated up and then turns back to a gel.