With regard to the subject of "Steam Punk", all I can say about that is it reminds me of Part 3 of the famous "Back To The Future" trilogy in which Doc Brown creates a flying steam locomotive time machine and comes back to say goodbye to Marty and his girlfriend. No more Delorean.
Another example would be the old TV series, "The Wild, Wild West," with Robert Conrad. That series mixed the James Bond spy genre with Old West villains who came up with fantastic steam powered machines and weapons. Now "funk" has become "punk". . . go figure.
Finally, the reference to model railroad steam locomotives being expensive and operating poorly is only partly true. Yes, they are expensive (so is all model railroad motive power in this DCC age) but they run very well. A friend has dozens of different types and they are sweet running, have sound, smoke, and all the details we only could dream about back in the 1950s with Varney die cast 10 Wheelers.
Richard