Things that don't appear to be working with 5.2
 

Feign Death - The button depresses for the 10 second delay, but there is no "Houwser has fallen to the ground," so that would assume that it didn't fail. However, on a typical FD, mobs con indifferently, but i still conned dubious to one. Another example was in PoNightmare, i was fighting a Wraith and tested it a couple times. It dropped me to the ground as normal, but the mob still attacked me. Note: This was also tested with 240 in the FD Skill.

Mend - (think it already ahs been mentioned) Button depress for correct delay, but nothing happens. (no "You mend your wounds and recover some health")

Lay Hands - Same as mend.

Tonight I'm going to test some class unique abilities (e.g. rogue sneak/hide) so ill edit this later.