When WoW itself crashes, you can find the logs (and dump files) that we need in C:\Path\To\WoW\Errors\. They're named by the crash date + time. A .txt and a .dmp. Just zip them up and send them to us. (The .dmp is important! It shows us some required memory addresses that the .txt file does not) Feel free to edit out your character name, etc from the .txt version. (The .dmp version doesn't show that info)
For any, and all 'reports', we need your full log file. (Again; they're created by date + time, but for when you started HB. We need the one where the issue was showing itself.)
Preferably, we'd like a 'time' when it happened, since some log files can easily be a few MB in size, and reading through all of it is quite a pain. So anything you can do to help narrow down where it is, would be helpful.
Lastly; if you're still having issues with the bugtracker, hop in IRC and talk to me personally. I'll try and help you. (Sorry, but I rarely read my PMs on here anymore, as most of them are just people complaining about things that have nothing to do with HB, or anything I can look into!)
As for the "Sync failed!" message, it can effectively be ignored. It's just a debugging message left in.
The next release will have more concise error messages when things fail related to auth, so people should realize that it's not a bug, but an issue with contacting the server itself.