Sorry to be so clueless...
And a specific question: can multiple apps attach to and attempt to control the same radio and slice at the same time?
Here's a link to the Wiki, http://wiki.flexradio.com/ .
There's a lot of information in this forum. I do a lot of searches when looking for details.
You may have already seen this, but here's a link to a post here called Studying the CAT Project . One of the replies I found interesting was from Eric who explained a simple sequence to connect to the radio.
Yes, multiple apps can connect to the radio at the same time. Commands are transaction based, so different apps know which responses are meant for them and can send/receive commands from the same objects.
I asked a similar question about a week ago and it was suggested to me a post by Eric: https://community.flexradio.com/flexradio/topics/first_steps_with_flexlib
Looking better at the software, you'll discover that each step illustrated by Eric is present in the Main class constructor (Main.cs). For a correct usage of the "slice" objects you have to look at the method "ConnectRadio" in the same class.
So a good starting point is to study the Cat project.
I don't know if I can do it, but I could post a pdf with the class diagram of the "flexlib". I extracted it with Visual Studio 2012 (Ultimate Edition). The class structure is not very complex, but there is a lot of hidden logic that needs to be handled through events. These events are really so many but also very helpful.
Just to share our experiences: I think the "Cat" project keep the whole state of the radio (in the class CatStateManager). So on the one hand the program receives commands from the RS232 and on the other it sends the corresponding command via the ethernet port. I still haven't understood how this really happens: for the moment I am stopped at the Execute method in the CatBase CatBase (CatBase.cs). Maybe further explanations by Flex Developer Team could help us.