Without reinstalling, is there a way I can delete all the data and the history and get back to how the system was when I first installed it (back to the initial epoch) while keeping my current schemas and projections?
You can use export_catalog() to export the table and projection definitions, drop the database, recreate the database, and then recreate the tables and projections. The export_catalog() won't include users or permissions - you would need to recreate those.
You could also write a script to TRUNCATE all of the tables. TRUNCATE doesn't maintain history.
I recall your database was having some issues with replay delete? You should also address the projection design issues that were causing that.