the second output argument of ProCombstateAnnotationsGet(...) returns shown/erased state - 0 is shown and 1 is erased ('displayed' and 'undisplayed' in Creo6 lingo). An annotation element is not going to be a member of the returned array if it had been never attached to a combstate. ProAnnotationIsShown(...) will return the global status of the annotation in a solid model - if it returns false I don't think it is necessary to drill down to combstates.
I do not know about deleted/undeleted states for annotations or annotation elements and if those things are in pro/toolkit in the first place. There are old enums from pro/develop days which become ProDrawMode in pro/toolkit - maybe this is the point of the confusion.
By the way, ProSolidAnnotationelemsVisit(...) is to be used for 'free' notes, refdims, etc... The function was not intended to be a global collector for all ( free and feat bound) annotation elements. For feat bound annotation elems one need to visit features in a solid and filter on ProFeattype and then visit annot elems in collected features.
HIH.