Same here. Free Republic is still Internet 1.0.
The only improvement I wish for is embedded video, otherwise it's perfect.
A simple and practical change would to do a dupe check after the submit button is clicked. Two posters search to see if articles “xyz...” was already posted. Negative search results so both start formatting up the post and then submit. Boom dupes. Post submit checking should be fast, assuming the titles are indexed. You could even limit the dupe check to within the last N days.