So if I understand, just losing your phone is safe, but if you find it again after losing it, you basically shouldn't keep using the phone before completely reflashing the device?
Well it won’t come back on in that case (the modified firmware will fail signature check.). But as you say you are still safe, just don’t unlock the device before reboot.
I think that depends on how it's set up, right? I rememember on my old iPod Touch with a tethered bootrom exploit, you could reboot without a computer but it would start up in non-Jailbreak mode. If you wanted to boot Jaillbroken, you had to find a computer. (This was the origin of the term "semi-tethered Jailbreak").
