To tell you the truth, I am a bit confused... just like Tomcat.

From your first post I had the impression that you would like to know that an error occurs before it really happens. Which would be rather hard because a DP Slave is not really smart, it has no eyes to see that someone comes and pulls the plug, it has no crystal ball to see if someone switches off the power... or something like this... I guess it would be hard to get something at this price level.

In your second post you mention that you do not want to get showers of errors... or Fault OBs if something happens. Well... I do not understand that either. If you lose a DP Slave, for example, you get one fault OB, the OB 86... not more. Well if you try to access the data of this DP Slave after that ... you will get a fault too... but this is a fault of your program... not of the System.
If you put an Input card from your slave, you will get an OB 83... not more... and you will get another OB 83 if you put it back in again.
If you try to pug a wrong card to the Slot you want to change you will not gat a fault OB, you will get a DP Diagnostics information... you have to evaluate in your program. Well... OK, you may get an OB 83 too... because a card is there again... true. But you will surely not get complete rush of OBs for each single input you had... this would be horror, true.

Additionally you mentioned that you want to have the Status of your PLC and its peripherals... I wonder, why don't you use the FB126?

Diagnostic package PNIODiag for diagnostic evaluation for PROFIBUS DP and PROFINET IO

here you even have an interface for visualization.

Best regards