Answer to Question 1: Yes, because the Live Mapping is built on top of the procedural model. Note, however, that there is an implied difference: In procedural model, there is "one" event notification (ItemChanged) for the change in the item's state, and it carries all necessary information with it (error information, OR the value/timestamp/quality). In Live Mapping, you usually map the individual pieces of the incoming data - such as the Value, or the Timestamp, or Quality. Now, in case of error, there is actually no value, no timestamp, and no quality, in the notification. There is nothing reasonable that can be stored into these members through Live Mapping. Therefore, in case of error (such as OPC server down or inaccessible), there will be NO UPDATE to members mapped as Value, Timestamp, or Quality, even though the notification HAS arrived. What you need to do, if you want to be informed about the error state, is to map a separate member with a mapping kind such as Exception, ErrorMessage, or the like.

Answer to Question 2: Yes - as described in Question 1.

Answer to Question 3, both a) and b): There is no "refresh" like this in OPC Data Access, therefore you cannot precisely do it "as the question is asked". But you can easily issue a Read instead.