I was reading that in the real world pilots should constantly check the morse code ident of the NDB to ensure they are recieving the correct signal. Is this replecated in FS and is the morse code signals reliable in FS and a worthy learning tool?
Not constantly, but yes. Once tuned in and receiving a station, it's a good idea to listen in on the morse code identifier. You don't have to do much... listen and then compare to the morse code listed on your chart. If they match, you have the right station.
Yes, this actually is replicated in FS2004. Just turn on the NAV radio ID button and you will hear the code repeated over and over
It is not only the NDB that should be ID'ed by verifying the morse code ID being transmitted but also VOR's. In the real world, it is a check-ride busting error not to ID each navigation radio station as you tune it in. It is a reliable way to ensure you have the correct frequency dialed in, that you are navigating on the correct radio, and that the nav radio ground station is in operation.
When you use the ADF, you should listen to the ID at all times because it does not have a failure flag like the VOR. The only way that you will know that it's failed is the loss of the ID signal.