Have done 10am flights several times. Only had one hitch and we still made our flight. I have no concerns booking a 9:30 or 10am flight if the ship is docking by 7am.
Our hitch: Last year on Emerald after Panama Canal. I had booked a 10am flight that got changed by Delta to 9:30. We were supposed to dock at 6am so I wasn't really worried about it. Our last port, had strong winds and we were 3 hours late leaving. Captain said he couldn't make up all of that time getting back, so I tried to call and see what my flight options were. None for that day, so they advised keep our current flight and see if we can make it.
Ship arrived back at Port Everglade at about 7:30, but they did not start letting us off till about 8:20. Lots of people trying to catch a flight. We were off and at FLL by 8:45. Got in baggage line, and a Delta rep asked if anyone was on the 9:30. They pulled a few of us out of the line and took us up and got our bags checked, and we got through security and on the plane at 9:10 and made our flight.
I try to stick to no early than 10am normally, which you should be fine if the ship is on time.