No worries.

Yep you're spot-on in this case, and as you say the software signing keys hasn't been compromised, though they aren't needed in service mode.

There are definitely ways the dongle keys could have been better protected (and I'm sure a few people are having some very serious talks about why they weren't), but have to give Sony kudos for having a system last 3 years without being compromised, and even now it's only easily broken at ring 2; the gameOS level of the system.