There is a bank and a full blown crafting area at the top level of Skarháld. But I rarely see anyone there. Why? Because it is a major PitA to ride up & down all these freaking stairs. People rather port to Bree or Galtrev and back to Skarháld than trekking to the top of the stronghold.
I'd love to have an instant travel goat that connects the top and bottom levels. This could be invisible at the beginning and unlocked by a quest (e.g. Black Book 8.7 or State of the Expedition). I bet a lot more people would use the facilities at the top then.