Well getting another more powerful board would be an option too here and flashing that with the software....there are a few raspberry-pi like options out there including samsungs exynos5 boards which are much more powerful and yet only sip marginally more power. dumping the image from this (if its on and SDCard so much easier) and putting it onto another controller would make the most sense here. Not trivial to be sure (I have had to go through this pain hacking a chromebook with the same hardware.  

Any chance we can get close up photos of the internals? Like the rasberrypi controller? There might be ways to make this thing scream with the exynos or other arm dual/quad core chips. Transferring the image to one of those and making it scream would be good. At least creates a setup for scalability. Right now this thing is running at what it needs to run at.