In the curses interface, allow the user to configure a window that is like permanent inventory view but only shows their equipped items, so that they can quickly see that they are lacking a critical piece of gear.

Shops should slowly regenerate new items on empty squares within the shop, because monsters continually spawn and death drop items. Possibly, the items only regenerate when you leave and return to the level, rather than doing it while on the level.

The room of gems in the Castle should never contain worthless glass. (Unspecified whether it should still contain gray stones, or exclusively valuable gems.)