AP doesn't need QSS or more armor. Lethality and AD items need nerfs.
Mages aren't supposed to have survivability through items outside of Zhonya's/Abyssal/raw health. They need to learn to use their range and CC, position and trade properly in laning, and stick with their team past that.
Certain AD items are too good though. QSS should not have the Mercurial upgrade and should remain neutral. The MR could be replaced with health instead too maybe. Edge needs a CD increase on shield active and removal of MR would be reasonable too probably. Remove shield on Hexdrinker, give a bit more MR on Hex and Maw.
Lethality needs nerfs in general.
needs some 
