The open source DocFetcher has indexed over 10.000 epub books for me. The indexing process is quick, and conducting a full-text search across all of those books (after indexing) takes only a few seconds.
FastCopy does it and is super fast as well. The usability could be improved, but its speed is awesome! Where Windows Explorer moved files at 800 kB/s, FastCopy reached 60 MB/s.
For the requirements:
moves files from one folder to another folder as the result of a drag'n'drop action like Windows Explorer
This is a bit tricky, because that functionality is ...