I feel that the dataset tag is a little redundant. I know where you're coming from, you want to avoid manually adding in the fault messages into the tags. I don't see much of a performance hit on this method though. Just make sure your scan classes are reasonable.
Look into using tag import for your tags. Keep a master list in a spreadsheet and make an export tool/script to output xml to put in your tags. Then just import all of your tags, even if just one alarm changes or is added.