1) Actually, the OP would have to fly 10,000 miles for Gold, and / or 20,000 miles for Platinum. And, contrary to your statement, the fare classes still earn per the AA chart
here . Where are you getting your (mis)information?
The purchased fare class points to miles earning ratio does not change - even for EXPs, or if you upgrade using 500 mile upgrades or eVIPs.
2) Seems right to me.
3) Good deal, and congratulations to you (both.) But do not expect you will somehow earn 1:1 in G, Q**, N, O**, S , it won't happen. And as the asterisks say,
** Tickets between North America and Europe, India, Asia and Latin America booked in O and Transatlantic tickets booked in Q are not eligible.