It occurs to me that there's another way of handling the "earth sense" for revamped, stripped-down dwarven race, one that doesn't require any of the balancing acts (level limits, experience point surcharges) suggested in the stripped-down fantasy races post. Furthermore, it fits the "general power/scaled power" template from the stripped-down classes without awarding non-humans bonus powers, and keeps things simple.
Race as class.
No, not the way it's done in BD&D. Rather, if you play a dwarf, you replace your class's general power with earth sense. You now know which way magnetic north is and can sense your depth underground, no chance of failure under normal circumstances (a loadstone might interfere with sensing north.) No need for level limits, class restrictions (except for setting purposes,) or disadvantages. Dwarves also get physical description labels of Short and Stout, which are "self-balancing" (drawback in some situations, benefit in others.) The rest is handled by cultural background.
I think in general this is a good, simple way to handle classes. Some races may optionally have additional powers, but these would be coupled with drawbacks of some kind.