I can sort of answer question 3...if the TSA's PreCheck hours site is accurate - https://www.tsa.gov/precheck/schedule, PreCheck is available from 10am-11am on a Thursday. It is not available before 10 or after 11. Seeing those hours was a surprise to me since I've never seen Precheck at T1 at JFK.

Please be advised that JAL does not participate in PreCheck so if AA can't issue the boarding pass for 8495 and JAL has to, it won't be available.