I fly online, but only on FSHost servers, not GameSpy.

No problems related to FSHost.

TiggerToo, on your Yaw Damper question - make sure you have your IRS systems initialized, make sure also that all your hydraulic pumps are commanded on and all pressure warnings are extinguished.

As for "why 3", well, why not?  Two are better than 1, and 3 are better than two.  The real reason?  Autoland.  You need to have at least 2 AP's online to have Autoland functional- so the third redundant system allows you to still get autoland if you have an AP system fail.

At least that's how I understand it.  ;)