I myself actually dun care that much about preventing people to get in. I just do as many backups as I can, as that's the only thing I consider data security. Including everything online and offline. But that's not to say I don't try quite hard to prevent issues with anyone getting in anywhere.
If I were as paranoid as you I wouldn't trust encryption, I would do my own nutzy way to store it in a HTML or even TEXT, and then replicate it along with many other stuff. The idea is hiding the password in plain sight, but only you know what to look for. Grab a digital book or something, make a simple rule only you know, and use it as your password. For instance:
The quick brown fox jumped over the lazy dog... and DIED!
The password here could be:
Tbjtd.D!2011 - There, I even added the year. Eventually I get used to typing it and I don't even need to look at the reference anymore.
As we were discussing, yes this is security through obscurity, but this is only for an individual. If you get such a random selection of characters in your mind only, and never write it down nor pass it along to anyone, there's conceptually not a safer password because it is unpredictable by definition (randomness). It only needs to be big enough to prevent computational power to brute force it. It's that simple.
So if you write it down in an unpredictable fashion and add a honeypot with all encryption and stuff you've talked about but don't add your main password in there, you just added yourself many layers of the topmost security while making a perfect and impossible to follow path that makes sense only to you. The point on writing it down in my suggestion is simply as a mnemonic device so you can remember your password may you ever forget it.
Keep in mind this is a very specific use case not meant to generate security measures for data nor encryption, but a password.
But if you want to rely on some encryption and don't know if you can trust Keychain.app (I know I can't), try the open sourced KeePassX, which is the only way to trust encryption, as I see it. You can combine it with Dropbox and try to ease up your mind by trusting your key will never leak.
I'm glad to see you actually found a "better" (at least if you only use macs) replacement for KeePassX (the DMG) and were even able to add an automated way to updating it through LaunchAgents. The rest is basically what I said above.
No encryption or security measure can be 100% trustable almost per definition but it's still useful as an extra layer if you don't care for calling attention to your relevant data and concentrating it into a big safe saying "here, try here and if you succeed opening this, you got it all" considering it is indeed very hard to break it.