1. These are (proably) negative (collections) accounts. They would stay on your file until 7y or 7y+180d from your DOFD. Chances are, they'll be deleted at 7y because the CRAs are pretty automated. Technically they could stay on your account until the entire student loan debt is repaid, but they probably won't (HEA requires them to stay reporting, but I also consolidated defaulted loans and they dropped right off).
2. Probably, because your DOFD is likely >7y (if your default is 2007)
3. It's not the negative payment history that is marking them as derogatory, but that they're collections accounts. I would wait to see what happens after those accounts are closed and your new consolidation is reporting. This could take a few months, it could be quickly (in my case, my collections closed very quickly, but it took 4 months for the new loan to show).