[LinuxBender]

What I described above puts me on your machine. This is not theory, it has been tested against many people. Legally of course.

[staticassertion]

So you were vague about where I execute the script. If I execute the script on my client, obviously you have my key, but that's not interesting. If I execute the script on my server, you do not have my private key, period.

This whole "I can ssh back to your machine past your firewall" is not a thing I understand, I am not aware of that capability in SSH.