V/A chat advice

"Steep" is sort of a relative term, and will be different in the context of any given developer's skillset (if you have a strong CS background, it will be less steep than if you are limited to web application development).

The FMIS scripting envirnoment is javascript (FMIs uses spidermonkey), so the syntax on the server side should be fairly familiar to anyone using other ECMA based languages. There are classes and methods that are specific to FMS, but the documentation should go a long way in helping you understand the FMS specific parts.

There are some prinicles that are completely foriegn to new developers coming from web application development. You'll need to gain understanding of the application and application instance (and lifetime) architecture, you'll need some understanding of how resources are allocated on the server side, and you'll need to understand how to properly configure FMS (or other RTMP server if you choose not to use FMS), and you'll need some understanding of dealing with varied network conditions and how they affect the streaming experience. You'll also need to gain understanding of how to secure the FMS application against abuse.

On the client side, you'll need to understand firewall and proxy concerns, device incompatibilities (not every camera / machine combination will work), environmental variables (for example, how to properly use AEC), and how to manage and maintain netconnections and netstreams (and how to deal with it when they break). You'll also need to understand that with every new flashplayer release, there is potential for something to come up broken (this has been true in the past few releases), and have to wait for another update for a fix. You also need to set your client's expectations properly... while most users will have a good experience, some will not, and a few will not be able to use the application at all.

When you say "buggy and unstable", there are actually a few parts to this. As I see things, the 'buggy" part tends to stem from applications that were developed without a solid understanding of the client/server architecture of RTMP applications, or recklessly without any means of handing network issues or human factors. If find that unstable applications tend to be the result of having been developed and deployed without understanding of the architecture or limitations of FMS.

As for security, it's up to you to secure your application. While FMIS supports a few limited methods of securing the server (SWF verification, IP allow / deny) they are somewhat wide-net in nature, and in my experience, don't offer the fine-grained access control you can achieve with application level code and interaction with external services.

While it's not all that difficult to get an application up and running, there is quite a bit to learn when it comes to building (what I consider to be) properly developed applications. If you're uncomfortable diving in to RTMP application development on a paid project at this point, you might consider farming out that part of the application to someone with some practical experience.