You get the configuration on ServerCommandService using the GetConfiguration method. You get video on the recording servers Image Server protocol.
The sample TCPVideoViewer shows how to get cameras and stream (the sample is c# .Net but it uses protocol methods so that you can implement the same in other languages and environments.)
Regarding to send alarm, to set up an event (definition) and an Alarm Definition is configuration job that is done in the Management Client (if not from MIP SDK code). The Configuration API is the API for doing configuration of the XProtect VMS including setting up event (definition) and Alarm Definition.
Please see -
Note: It is possible to submit an alarm to XProtect without having an Event (definition) or Alarm Definition. Please see this knowledge base article: https://developer.milestonesys.com/s/article/Create-an-alarm-from-a-MIP-SDK-based-application
Note that the article refers to a sample and that sample does not use the protocols directly.
For live stream URL, Mobile server might be interesting for you - Mobile Server was developed to assist mobile and web clients to access Milestone XProtect servers. Please see Mobile SDK and find Log-in and show streams -