As far as the items logged, I believe you can trust those timestamps. Unless you have your server time off or something odd, those are logged as they happen.
I have seen the extra launches on our system as well. We tend to launch our packages in a new window and for us, I believe the extra triggers may be due to popup blockers and similar. So, it triggers a launch, but the browser blocks it and then logs another launch as the popup is allowed. That is just a theory though.
The system I believe logs a logout for the user, but not timeouts. We actually modified ours to log a few more things than are logged by default, but it was a code change.
As far as your core.total_time, that is totally dependent on your SCORM content and what you used to build it. I have found that to be much less reliable as students manage to reset it or odd timeouts throw it off.