If the information is provided by the hoster we generally include it within our plugin dev. If its not we go on error clauses which only usually get listened for as a POST event. We rather not delete or remove any accounts from jdownloader via any automated process, as could remove accounts by error
eg. plugin errors or hoster issues. Just like now many hosters are suffering under heavy loads due to filehoster closure/restructures, accounts can and are been disabled frequently. Which means your idea wouldn't work well in those situations.
Notify maybe useful to the user so they are aware that the account is disabled for xyz reason. What your wanting to do is more GUI and listening to events.
You've most likely already done this ...
setup guide:
http://jdownloader.org/knowledge/wik...nt/get-started