Two things I would have done differently...
First I would not have used a fortress as a rally/heal spot. Use a city with a barracks. If none of the captured cities has a barracks then rush one. Units in a city with a barracks will heal to full in one turn if you don't move them. This allows quick recovery and helps prevent loss of defenders (they only need to survive with 1hp to be at full health next turn.) If you are worried about the defensive value of the town because it is too small or some such then be sure to rush some city walls.
In regards to Miami, if you plan to make your Alamo stand there the Barracks is essential. While having the airport there has advantages I would build it in one of your previously captured cities farther back from the front lines. It adds an extra turn for reinforcements to arrive, but at least your airport cannot be taken so easily, or bombed. In this situation, with your quickly dropping population I'd also try to rush some walls. Once you get your fighter support then civil defense is another good item to rush. If you think you can defend it, create a radar tower. Once you get up a few essential structures and fighter support most attacks will be like waves breaking on the rocks and you should be able to make up for losses by reinforcing from your airport.
I'm not saying that those would work, but that's just what I would have done differently. =)
First I would not have used a fortress as a rally/heal spot. Use a city with a barracks. If none of the captured cities has a barracks then rush one. Units in a city with a barracks will heal to full in one turn if you don't move them. This allows quick recovery and helps prevent loss of defenders (they only need to survive with 1hp to be at full health next turn.) If you are worried about the defensive value of the town because it is too small or some such then be sure to rush some city walls.
In regards to Miami, if you plan to make your Alamo stand there the Barracks is essential. While having the airport there has advantages I would build it in one of your previously captured cities farther back from the front lines. It adds an extra turn for reinforcements to arrive, but at least your airport cannot be taken so easily, or bombed. In this situation, with your quickly dropping population I'd also try to rush some walls. Once you get your fighter support then civil defense is another good item to rush. If you think you can defend it, create a radar tower. Once you get up a few essential structures and fighter support most attacks will be like waves breaking on the rocks and you should be able to make up for losses by reinforcing from your airport.
I'm not saying that those would work, but that's just what I would have done differently. =)