1. For the Chase United Explorer card offer "Earn a $300 statement credit and 40,000 bonus miles", I see this wording under Offer Details "....we may be required to send you, and file with the IRS, a Form 1099-MISC (Miscellaneous Income) ". If I end up getting approved and the $300 is my only monetary reward from Chase this year (I have neither earned any other bonuses from Chase cards nor earned any referrals from Chase this year), does Chase still send 1099-MISC when the amount is below $600?

2. "If you're instantly approved you can use your card today to purchase your flight, and the statement credit will post on the same statement as the purchase."
If I get an instant approval, am I able to use the temporary card number for several United flight transactions or is the temporary card number only valid towards one United flight?

If I understand correctly, any purchase amount (even $1) should qualify me for the $300 statement credit?