ion201

rsync can be run in cygwin.

For Linux, dm-crypt/LUKS for full-disk encryption (this is already the default on many distros) and eCryptfs for less complete or individual file/directory encryption.

Open hardware

Nope. Its i7 cpu is definitely not what I would consider open hardware. So then what's the point of this? If there's nothing 'libre' about most of the hardware inside then it's just a normal i7 laptop with Linux pre-installed. I don't see how this is any different than just buying a laptop and immediately replacing everything on it with OSS.

Putting a python game on a phone is definitely more of a problem

Not necessarily. kivy[1] is an alternative to pygame (for desktop builds, it uses pygame/sdl under the hood iirc) but it supports exporting to android as well as desktop platforms. I haven't done a ton with it so take this with a grain of salt, but it looks like it could be a viable option in this case.

[1] https://github.com/kivy/kivy

Care to elaborate about that? I don't see the security concern if the data is encrypted on disk and both ways over the network. I doubt they would just leave the private keys to hang out on the server for anyone to take.