FBLA=Future Business Leaders of America. This may be their national convention. I attended one when I was in High School (in Houston). The kids that attend the national conference have won state level awards or were selected as state representatives. They have worked hard to get here. My year ('85) the kids were all very well chaperoned and very well behaved. Our hotel didn't get wild until the college delegates came in the last couple of nights we were there. Of course things can change over 20 years.
I would not hesitate to stay with this group, but I'd find it fun since I was a state winner and president of my HS's club.
As far as being at the Swan during a conference, I've done that too. I attended a conference and the conference area is on the main lobby floor and separate from the normal traffic for the hotel. You may have business people in the lobby and lounge areas enjoying their cocktails in the evenings, restaurants at lunch may be more crowded, and the pools may be closed for private parties. Honestly, the folks seem to keep pretty much to themselves.
The Dolphin tends to host fewer conferences and I've heard that it is very family friendly. Conventioners may spill over into the ballrooms of the Dolphin for meals and afterhour entertainment. Hope this helps.