1. Yep they time out. But I've seen first hand, that a domain can be re-issued a second manual penalty ...six months after the first one was issued. No new links or content was added to the site, no attempt was made to clean it up.
2. There's no one way for it to happen. People who've submitted multiple requests, seem to have better luck in getting more direct email responses though. It probably also helps to have what would otherwise be a good site if it weren't for bad links.