A Dwarf has the power of infravision, meaning that their eyes can detect heat radiation and thermal currents, as well as infrared radiation from living organisms and machine devices. It does not, however, allow the character to unequivocally see in the dark. A Dwarf in a locked, unlit, walk-in freezer would be just as blind as a Human. Moreover, a Dwarf could not read maps or books in the dark unless the text or images were drawn with special ink and illuminated with a radiant infrared source.
For combat purposes, however, a Dwarf does not suffer penalties to attack during poor lighting conditions, provided that the targets are living organisms (Undead do not radiate heat because they are, in fact, dead.) Dwarves are partly colourblind (they cannot see blue or purple -- these colours look gray and pink respectively.) They suffer a -2 vision penalty in very bright light, and save at -2 against light-based attacks.
A Dwarf's ability to detect iron and steel works only on those two metals (because they are magnetic metals). Their power cannot be used to locate silver and gold. Their power to detect north fails only on a critical fumble.
A Dwarf's metabolism is greater than an Elf's but less than a Human. 2,000 calories per day and 6 hours sleep per night is sufficient for a Dwarf. A Dwarf’s dietary requirements are a lot like a Humans. Given their subterranean lifestyle, fresh fruit is always in high demand in their communities.
Dwarves and Changelings have always had a mutually beneficial trading relationship. Changelings are highly effective farmers (Dwarves are not), and Dwarves are very skillful blacksmiths (most Changelings lack the physical strength to do this task well). Thus, these two races have a long history of trading tools for food. The Isle of Gales has a fairly profitable opal mine that is owned by the Changelings, but mined by the Dwarves. The two races split the profits.