Question 1: Depending on the contracting officer or contracting organization's policies, the bid opening officer may be the contracting officer, the contract specialist, or someone who is strictly dedicated to serving as the bid opening officer for the contracting office. FAR 14.402 describes the duties of the bid opening officer. There may be additional duties prescribed by the contracting organization.
Question 2: The duty of appointing a bid opening officer may be agency specific or may be in accordance with the contracting organization's policies.
Question 3: Generally, the contracting officer or designee is responsible for signing the Abstract of Bids, SF 1409.