1. About 7 years from the filing date.
2. No.
3. After USCIS approves the I-130 it will be sent to the NVC About a year before the visa becomes current, the NVC will "unlock" the case and contact the petitioner to pay the AOS and IV fees. At that point your parent and your brother will complete the NVC steps.
If your parent becomes a USC, the category will change from F2B to F1 and it will take an additional 1-2 years for that category to become current.