ok makk, here is what i did. i unsquashed the system.sqsh. i didn't change anything at all, then resquashed the system.sqsh. i am getting stuck in the boot loop (nexus splash screen).
the files stays the exact same size so i'm not sure what i'm losing in translation here.
i'm afraid without running linux to get into the system, i can't go further.
i'm still playing with it, so if i find something new out, i'll post it up.