Hi there,
I have read your project and it is interesting. In fact, I have built several signal generators and bridges between MET4 and external Broker APIs. I am an IG engineer and I work exclusively with MT4 solutions.
The most important part to consider in your project, no doubt, is the bridge from MT4. Once you this Bridge (preferable built as a C# DLL), the rest is fairly easy. You can send this signals to your server and from there broadcast the Signals that arrive to one or more listeners or accounts in other Brokers hosted in your server or remotely. There are many approaches you can implement, in order to get your structure working as you need, anyhow it will all depend obviously on your specific requirements.
I also offer you to build your MT4 Bridge entirely in C# instead of C++ as traditionally has been. In the first place, to avoid the cumbersome dependency with C++ Redistributalbes. With C++, you need to install exactly the same C++ Redistributable in which the Bridge was built in, otherwise it will start to fail. With .NET instead, it is usually already installed on most modern machines, so you don't have to worry about compatibility issues with your MT4 extensions. Not to mention that C++ is also by far more error prone than it counterpart C#, which will translate in savings in maintenance of your structure among other advantages.
Well, I think that is all by now. If you have any question just send a message.
Regards,
John P.