Thinking about the cars, it's entirely possible that AAF solicited a presentation from the Hi-Level folks to hold up next to the European builders. Even though maintenance would be a pain on the Hi-Levels, it's possible that were the Hi-Levels to only cost, say, $1 million apiece (or less), or even to be picked up on a medium-term lease, they might make sense to start things off with even with expensive maintenance if the alternative was a set of $15+ million trainsets.
Likewise, with a lease deal, AAF could order their trainsets, lease these to get their operation going, and use these until the trainsets actually get delivered. I don't know what the delivery timeline would be, but I can believe them being able to get the tracks in place by 2014 but the trainset acquisition process taking longer to get full delivery of a set of sets. The bottom line is that I wouldn't be surprised if they solicited this offer alongside planning an equipment order from someone overseas and/or at least looked at this as another option.
Shifting gears slightly, the through ticketing decision might be a temporary move (to dodge STB jurisdiction for as long as possible). It's also possible that if they go forward with expanding the operations, that JAX-MIA might end up as a nominally separate entity (they haven't had any problems dividing up their corporate persona yet, so another one, AAF-North, could happen that would offer through-ticketing but might have enough separation from the other entities to keep them safe from STB oversight) with through ticketing (since that would likely involve an "actual" interchange with Amtrak whereas both MIA and ORL are set to be clunky cross-town connections that would discourage a through trip for anyone but a railfan, since the southern FL cities are almost all also covered by Amtrak at a separate station at the present time).
On the 16-19 daily round trips, that would seem to imply the following (if I had to guess):
5 AM-9 PM hourly departures M-F, with an additional departure either at the half hour (7:30 AM and 5:30 PM would be good candidates) or at a "chaser" time (i.e. 7:05/7:10 and 5:05/5:10) each way during peak times. On weekends, cut back the 5 AM departure and the extra peak times and keep most of the rest of the service running (considering the tourist-heavy nature of things)...which would allow for things like a day-trip to Miami (or Orlando, especially if the line eventually gets extended out to the Disney side of town).