To scrape cover instead screenshot you can go to "option configuration" and choose what you want as "picture"
You also can try some MIX template (juste relaunch the wizzard and choose a (MIX) profile)
For the scrape speed it depend on many thing.
The number of person scraping at the same time (server overload)
The number of thread you use (default is only 1 thread, but with a registration on http://www.screenscraper.fr and some metada or media submission you will gain very quickly new thread 😉 )
For your info, 1 thread mean : you scrape rom 1 by 1, 2 threads : 2 by 2, 3 threads : 3 by 3, and so on...
