I would use all e upgrade credits. I will have a few expire, but its so nice to be able to move to first class on a late or early flight. Usually it is about 6 credits to upgrade 1 way to Toronto/LA.
Unless you are anticipating a long layover and travel with someone, I dont see point in using guest passes for lounge.
"I believe that banking institutions are more dangerous to our liberties than standing armies. If the American people ever allow private banks to control the issue of their currency, first by inflation, then by deflation, the banks and corporations that will grow up around the banks will deprive the people of all property until their children wake-up homeless on the continent their fathers conquered."
-Thomas Jefferson 1802