Hi,
I guess you’ve probably already tried it yourself. I have a LimeSDR USB, but I would expect the Mini to work well also, and that your points 1, 2 and 3 are correct and that you can use the Mini to control the switch.
For point 4, it might be quite some work, depending on what you want exactly. You can check this comment for something that might help but on the LimeSDR USB. The idea is to synchronize the Lime with another one (or with any other device that can be connected to the GPIO of the board).