Congrats on the OW cert! What a way to get started. I think Roatan is a great place to learn. I know my sister felt that way going through her own OW course during this trip. So glad you had a great time! Thankfully, the rain stayed away for most of your vacation. Shame, though, about all the lionfish (our experience was about the same as yours; saw them on the vast majority of dives).
Nice report. My wife and I were at Anthony's Key Resort from the 10th to the 19th and lost a day and half of diving in the middle of our trip due to the rain. Still a great trip! We actually did our OW cert dives on Fri and Sat and managed to get in 19 dives during our stay. We also saw a lot of Lionfish (on all but one dive, the El Aguila dive, I think).