FTB: quarry ettiquite
For those making quarries outside of the city - It would be good if any old vacant quarry sites could be at least fenced, to make them safe. Particularly if those quarries are somewhere where people are likely to want to wander about (particularly places like the myst)
There should be ample cobble available to make cobble fencing, which will stop anyone falling in. Not everyone will have rubber boots or whatnot.
On that same note... if you're going to cover them up, put a couple of layers of something like cobble - not just one. If a creeper explodes on it, and it's only one layer, it's likely to break right through.