There are a lot of expressions missing from c2, and I can't test c3 to see if there are still missing there.
Expressions like object.visible or layer.visible are missing. Also, mirrored,flipped. Also hotspotx,y for 9patches/tilebackgrounds, etc..
Basically their are a lot of stuff I'd like to use in expressions. The workaround is creating instance variables to store their states, but I shouldn't have to do this for default object properties.
also, another example is checking if groups are active- there are conditions for it, but no expressions.
Things like "is visible", "is mirrored" etc are better as conditions; expressions don't really properly support a boolean type. Additionally the object's normal X/Y co-ordinates correspond to where the origin is. For other expressions it's often straightforward to add new ones, so as long as you list the ones you want and it's clear what you want we should be able to add them.