Were you able to figure this out? I ran into the same problem with FMServer13 where I did not create the Elastic IP until after I installed FMServer13.
To be honest, I have to say that I don't remember clearly enough for you to rely on what I say, but here goes:
I abandoned Amazon recently because I could not longer deal with the nonsense about their security methods. I tried Rackspace for a month and eventually dropped that too i favor of MacStadium which is not a virtual server but an actual Mac Mini that is rented to you on an exclusive basis for less per month than Amazon or Rackspace, with the ability to upgrade it any time to newer or more robust configurations. They even allow external USB devices for $10 extra.
The Amazon method of creating IP addresses absolutely requires an elastic IP number. I had one, but I can't recall if it required reinstall of FMS or if there was a sequence involved in the installation. It's possible that all I had to do was re-deploy after creating the elastic IP, or maybe reboot. But I also remember from past experiences with FMS-11 on my own WIndows server that there is a sequence of (1) uninstall FMS, (2) uninstall IIS, (3) reboot, (4) reinstall IIS, (5) re install FMS that works as FM support says, and whenever I tried to avoid doing it that way, I ended up doing it that way anyway.
In my case, I needed to be able to access my server with FTP as well as FileMaker. The Amazon "security groups" were a nightmare. Whether I had the ports specificed, or whether I had all the ports wide open and the Windows Firewalll turned off, I could never get it working right. Shortly after I got FMS-13 installed, I gave up and went to Rackspace, but when I had FMS-12 installed, the virtual machine was working with IIS and I was able to use the server Admin Console both locally and remotely, but I always had issues with FTP. I tried using Timbuku Remote also, and with limited success.
One thing I do remember with clarity is the fact that my "micro instance" was running fine with FMS-12 but FMS-13 would not install because of insufficient RAM. I upgraded to the "medium" instance which gave me 3.75 gb of RAM, so I know that FMS-13 was running for a while before I abandoned Amazon. I also purchased there business level support, but when I added up all the extras, it made me wonder if it was really the bargain I expected in the beginning. Moreover, everything I was reading about Web Direct suggested that I would not be able to get by with 3.75gb RAM.
Rackspace gave me 4gb, but MacStadium gives me 16gb and for less money. Plus, I can install whatever I want without having to bother with Windows firewall issues. Moreover, I have figured out how to locate some web files that don't need the Mac OS-X web service or DNS, so that they can be reached by Apache using FileMaker's control of port 80.
Hope this helps you.
The AWS host runs on a private IP and the Public IP is NAT (regardless of Elastic IP or not) So from the servers perspective it's running on the private address. The Elastic IP just gives you a static IP that you can associate with an instance.
Where this comes into play is if you take advantage of auto-scale (which can also be used to "auto repair an errant instance". You can script the IP address associations such that a newly auto-recovered server can bring up the same address as well as mount EBS volumes etc.
With Elastic Load Balancers, you can do SSL offload where the SSL cert is installed on the load balancer which then gets around this ssl connection issue but that's not really appropriate for filemaker given at least out of the box, no real support for working in a load balanced setup. You could be silly I suppose and front it it with an ELB with a single instance and use SSL offload.
With respect to the bare metal hosting vs the virtualized hosting, they each have their pros and cons. I have numerous servers running other applications (non-Filemaker) in the AWS environments leveraging many of their services and I've had tremendous success with it. Speed of recovery and ability to have applicaitons in multiple regions (data centers) and even move applications between data centers quicky and under programatic control is where the virtualization comes into play. That type of flexibility is likely not something your typical filemaker hosted solution requires or you'd be using a different architecture, I presume.
I've also had a single filemaker 12 advanced server running for well over a year with no problems but it's a lightly used server. I've considered MacStadium as well for some of my internal applicaitons. I've been waiting for them to support Mavericks before I give them a try. Last I chatted with them a few weeks ago, they were waiting for some bugs to clear before they supported it.