OK, there seems to be lots to learn for you, which is good


dd is an utility to create filedumps, you can use it to copy a partition or whole disk to a sdcard for example.
tar is a backup utility that will pack the files on a directory structure to an archive, the result will be smaller than a whole partition dump with dd but contain the logical structure in the archive. When expanding it the result is not a bit-by-bit copy of the *physical* partition layout but in most saes it does not matter.
rsync is an utility to make backup over network, I use it to copy the content of my device to my cloudserver.
Usage of all these and more can be found on the net and relevant manpages.


I would not recommend that to you now as I think you need to hone up your linux skills first a bit more


It's a continuation of the work done in Nemo/Mer for some time... used to be an open alternative for Harmattan on N9 using the Mer codebase.


Of course, that's the whole point
You can even patch the system live, though many modifiations require a lipstick restart to become active.


By use of ssh I mean it is all that is really required for connection. I think there are also some guithingies but I don't really know as I dont't use that kind of stuff.

As for creating applications you need the development framework for SFOS, maybe you meant that?