Native associative arrays would fix half of these problems. If you have a AssocArray, you could define and fill it as so.

Variant[""] Person 

move "sean" to Person["name"]
move 49 to Person["age"]

showln (Stringify (AssocArrayToJSON(Person)))
which would output
You can add/miss whatever fields you want in this scenario, and referencing an element is as easy as :
if (AssocKeyExists(Person,"name")) set field_changed_value of oUser_DD field to Person["Name"]
I believe that associative arrays would be as much of a game changer for dataflex as Native Arrays were. Especially at a time when we're throwing more and more JSON around. Associative arrays could map really smoothly onto JSON.