Re the original animation trigger issue: I don't think there's an issue with the trigger itself; the trigger is firing ok. The problem, from what I can see, has more to do with the Set Size command. It seems that because your animation have different sizes, it somehow gets screwed up.
I think that, internally, C2 applies a scaling factor when you Set Size by pixels. If Animation2 has 102x103px, and you set the size at 110,110, you set the scaling factor at 1.078.
Then Animation2 finishes, and then goes to Default animation (250x250px original), which then gets scaled to 269px. (250 x 1.078 == 269px).
Then you apply a size of 64,64, and the result is 156px. Why?
Well, I think it's because the 64,64 is applying a scale against the original 110,100 (1.078 scaling). So:
64/110 == 0.5818
And so Default animation new size is 269px:
269 x 0.5818 = 156px
In a word it assumes the new scale, but that doesn't mean it's necessarily the same pixel size. My recommendation is to compute for scale based on your expected Sprite resolution for a particular animation, then use Set Scale instead of the Set Size.
N.B. I'd consider this a bug in Set Size, not Animation Trigger. Who wants to report it?