XBee communication between routers and coordinators

Good day everyone!

I have 5 XBee Series 2 2mW modules wherein I'll be using them to communicate in some specific way with each other, however I don't think I have encountered any forum or site so far which discusses the answers I need. Most of all, I still consider myself very new in using the modules. I'll be using this for our project about wireless sensor networks.

In the following scenario, please assume the following components connected to each other:
a. Router nodes: smoke sensor, LED and buzzer, XBee module, Arduino (Pro Mini, Uno R3, etc.)
b. Coordinator: XBee module, LED, Arduino or Raspberry Pi

So first of all, I have 1 coordinator and 4 routers running in API mode. I need the routers not only to communicate with the coordinator by sending specific data, but also with other routers as well.

So for example, one router node detects something (e.g. smoke), it triggers an alarm towards the coordinator. The coordinator in turn produces a signal (e.g. turning on an LED) that confirms it received the signal. Then after a certain delay, the router node which detected a smoke sends an alarm again towards every other node in the network. This alarm will activate their LED and buzzers.

So my question is, is it possible to do this with router nodes?

Notes (these are my assumptions and please correct me if I'm wrong about any of them. Thank you so much):

  1. My understanding is that XBee modules are only capable of sending data towards a single destination.
  2. Then if not, is the coordinator the only one capable of being able communicate to all other nodes aside from being the only one able to actually receive data after configuring all the modules? Thus, it should be the one sending to all the routers to activate their LED and buzzers.

It gets more complicated as I try to look for how-to's online since there some editing on some parts such as destination address lows and my addresses, which in my part would not make some sense when I try to think of the case above based upon my understanding.

Sorry for the long post, but I hope this post may be of use to others since IoT is gaining more traction for monitoring applications. This may as well add some documentation regarding the use of XBee modules. Thank you.