Thanks for your response! I like the idea that this could be a standalone way to capture first-person accounts as well as a way to launch more in-depth/traditional oral history interviews.
Some of your requirements remind me of the National Library of Medicine's video player:
"NLM Video Search accurately and quickly searches digital videos with embedded transcripts. In addition to offering a full-text search of a film’s transcript, the tool graphically displays where a search word or phrase occurs within the timeline of a film. ... NLM Video Search is based on a combination of open-source and inexpensive commercial multimedia tools enhanced with speech recognition technology."