Your error logs shows no errors after April 8. This means, after that date, either no errors happened, or Couatl hasn't even started.
If it doesn't even start, if you are *really* sure you don't have an antivirus (not even an anti-spyware), the most likely cause is missing system libraries from Windows, you can't just remove the VC++ (NOT VB!!) runtimes, you also have to reinstall them, and usually run a complete Windows update AFTER reinstalling them, because Windows update will likely update them again.
Another way to fix this, is to do an FSX Repair, it can be done without uninstalling any addons.
And besides, there's no need to install the Addon Manager or a special "order" of installation. GSX comes with the Addon Manager and everything else needed for it to run. If it doesn't run, the cause it's not the installation, but something else in your system that is preventing it to run.
Another thing to check, is if you have inadvertently put "Virtuali" under the untrusted publishers, so nothing signed by us will run in your system. Check in the Control Panel, "Internet Options", select the "Publisher" then the Untrusted Publishers list, and be sure we are not there.