1. It took me about six months, doing 10-25 a day, with a 90% retention rate after 6 months.
2. I don't know, but the last few months Oha Suta has shown a trailer at the end of the month, so I was making a guess. Looks like we won't be getting one at a predictable time. Although there is still one other video slot on the official site, so there will be a trailer or video coming at some stage.