I don't see any problem getting your passengers to the ferry terminal on time for the 10am. Get underway by 7:30am and you will be fine. Call ahead to the charter company and ask then to have a taxi on standby. The concern would be whether the 10am is running that day or running late. If all goes well they should have no problem making the 2:30pm flight. The lines at C&I and the airport will be manageable in June.
Regarding AA's three hour rule that does not apply if you check in on-line. Check in on-line and its 90 minutes before departure.