Glad you are enjoying your trip to Austria!
Yes, the KHM is great, like you said, there is much more to see than coins. Well worth a visit for everyone interested in history.
I don't know how many days you have left, but I have a few recommendations for you:
If you are interested in art, I would recommend visiting the Schloss Belvedere Museum. They have a permanent expedition on Gustav Klimt, Egon Schiele, etc... Also, if the weather is nice, Schloss Belveder has a beautiful garden.
If you like churches, I recommend visiting the Stephansdom and the Votivkirche.
If you like hiking, there is a great path going around and on the "Kahlenberg", start of the trail is reachable by public transport. On top, you have a great view of vienna.
Should you get bored of vienna, you can always take the train(Westbahn) to Salzburg (one way takes 2:30 hours).
The 26th October, is austrias state holiday. There will be a parade by our military on the Heldenplatz.
Just be careful stores, museums, etc... will be closed on the 26th.