Playing FLV in Silverlight - What You Need It For

What am I talking about?
FLV is, roughly speaking, a video file format played by Flash applications on the Internet. I want to teach Silverlight applications to understand this format just like Flash does.
The purpose of this post is to understand the need for using the FLV video container in Silverlight applications. I also want to note that with Flash I worked enough and ate more than a dozen tablespoons of tar and just a couple of tablespoons of honey. And finally, do not judge strictly, this is my first post.

So, let's begin.
First, let's define the terms.
Flash is a program written using technologies from Adobe Flash.
Silverlight or simply SL is a program written using technology from Microsoft Silverlight.
Flv- video / audio container played by Flash.
MP4 is a video / audio container that is accepted by most existing players.
Smooth Streaming is a technology that allows you to play videos with variable quality depending on the network bandwidth.
RTMP is a special protocol for exchanging data between a Flash application and a server.
.NET is a platform for executing and developing applications from Microsoft.
Visual Studio is a development environment for the .NET platform from Microsoft.

To begin with, we’ll think that using SL, it’s possible to play video in the FLV format. The question is, why is this necessary if there is already a huge selection of players written in Flash?
There are several reasons for this:

1. playback of one database of video clips for users with Flash and SL applications, i.e. universality;
2. SL provides a more flexible architecture for writing a video player. In short, you can do something on SL with a video stream, which is not possible in Flash. Users watching videos in SL will have some advantages over users of Flash players, namely: Smooth Streaming on the client side, no RTMP protocols, upload video only a minute in advance, protection against network breaks, downloading video to multiple streams - especially important , and much that I have not yet come up with;
3. why exactly FLV, and not, say, MP4? Because, in my opinion, the FLV format is more suitable for transmitting streaming data than MP4, and the very clear documentation of this format also plays its role;
4. SL is a booming technology, the support of which needs to be done now, so as not to be left behind, but also you should not forget about the majority of users who have not yet installed the SL extension;
5. As a programmer under .NET, it is much more convenient for me to develop applications for SL using the familiar Visual Studio programming environment, and a familiar, albeit cropped, set of classes and libraries.

Of course, if you want to make money, then these reasons are not enough, but good things were not done for the sake of profit.
I would like to know your opinion about such a development - usefulness and prospects, as well as possible pitfalls, such as Adobe’s rights to the FLV format.