First off, I like the idea of a hash chain, so that all log entries can be check for authenticity. The issue with the first hash can be solved easily by, for example, printing it out and tape it to the machine (maybe with a seal and some holographic prints, so that even a physical attacker cannot change it).
But then I don't get why the logs need to be in a undocumented binary format, inaccessible to anything else. We all know that security though obscurity is a bad thing, and text format can accomodate anything. I don't buy the argument of "easier to analyze programmatically" argument: we can all use XML or JSON or some other organized text format if that is one of the needs. It also facilitates ease of recovery in case of, say, a disk failure.