A couple of annoying things which seem to trip me up occasionally:

1) Click someone in your friend list -> default option (the one under the mouse pointer after you click) is remove friend
2) Click adventure on the right of the screen -> default option (same as above) is cancel
3) accidentally click cancel and the 2 options are "ok" and "cancel"

with the 3rd, its kind of instinctive that you don't want to click cancel after accidentally hitting cancel.

Could these be moved somewhere else so they aren't so prone to being used in error?